Mohd Faisol Mansor

Transcription

1 Mohd Faisol Mansor

2 TABLE OF CONTENTS CHAPTER 1 : INTRODUCTION TO CHEMISTRY Page 1 CHAPTER 2 : THE STRUCTURE OF THE ATOM Page 5 CHAPTER 3 : CHEMICAL FORMULAE & EQUATIONS Page 22 CHAPTER 4 : PERIODIC TABLE OF ELEMENTS Page 54 CHAPTER 5 : CHEMICAL BONDS Page 79 CHAPTER 6 : ELECTROCHEMISTRY Page 100 CHAPTER 7 : ACIDS & BASES Page 130 CHAPTER 8 : SALTS Page 148 CHAPTER 9 : MANUFACTURED SUBTSANCES Page 175 : IN INDUSTRY

3 mohd faisol mansor/chemistry form 4/chapter 1 CHAPTER 1 INTRODUCTION TO CHEMISTRY Chemistry Is the study of the composition, structure, properties & interactions of matter. Uses of Chemical Salt (NaCl) Vinegar (CH 3 COOH) Tiles/Cement (CaCO 3 ) Careers Doctor Chemical Engineer Geologist Biochemist Pharmacist Chemical Industry Petroleum Food Chemical Substance Electronic Agriculture Contribution of Chemical Industries Financial Job opportunity Development of country Scientific Method : systematic method used to solve problems in Science. Making Observation Making Inference Identifying Problem Making Hypothesis Collecting Data Planning an Experiment Controlling Variables Identifying Variables Interpreting Data Making Conclusion Writing Report 1

4 mohd faisol mansor/chemistry form 4/chapter 1 2

5 mohd faisol mansor/chemistry form 4/chapter 1 Classify each of the following element into their group. Hydrogen, H Oxygen, O Zinc, Zn Chlorine, Cl Potassium, K Silver, Ag Sodium, Na Carbon, C Phosphorus, P Magnesium, Mg Sulphur, S Fluorine, F Aluminium, Al Lithium, Li Barium, Ba Copper, Cu Bromine, Br Lead, Pb Neon, Ne Argon, Ar Calcium, Ca Helium, He Iron, Fe Iodine, I Metal Atom Nonmetal Atom 3

6 mohd faisol mansor/chemistry form 4/chapter 1 Classify each of the following element/compound into their group. Sodium chloride, NaCl Hydrogen gas, H 2 Chlorine gas, Cl 2 Lead(II) oxide, PbO Aluminium oxide, Al 2 O 3 Silver bromide, AgBr Carbon dioxide, CO 2 Naphthalene, C 10 H 8 Sugar, C 6 H 12 O 6 Copper(II) iodide, CuI 2 Oxygen gas, O 2 Magnesium oxide, MgO Zinc chloride, ZnCl 2 Methane, CH 4 Ethanol, C 2 H 6 O Water, H 2 O Ionic Compound (Metal Atom + Nonmetal Atom) Molecule (Nonmetal Atom + Nonmetal Atom) 4

7 mohd faisol mansor/chemistry form 4/chapter 2 CHAPTER 2 THE STRUCTURE OF THE ATOM Element Matter Anything that occupies space & has mass. Substance that consists of only one type of atom. Kinetic Theory of Matter Compound Substance that contains two or more elements that are chemically bonded together. Type of Particles Atom Molecule Ion Atom Smallest particle of an element that can take place in chemical reaction. Ion Is a positive charged or negative charged particle. Matter is made up of tiny & discrete particle. Particle vibrate, moving & collide with each other. Particles move randomly. There are forces between the particle. Stronger the forces, particle close to each other. Higher the temperature, higher the kinetic energy of particle. Molecule A group of two or more atoms which are chemically bonded together. Physical State Solid Liquid Gas Subatomic Particles Electron Proton Neutron Diffusion Is a random movement between different particles from high concentration to lower concentration. 5

8 mohd faisol mansor/chemistry form 4/chapter 2 Atom, Molecule & Ion Atom + Atom Molecule (ELEMENT) + Atom Atom Cation Anion Molecule (COMPOUND) Ionic Compound Example: Formation of WATER Water Molecule + Oxygen Atom Hydrogen Atom A Glass of Water 6

9 mohd faisol mansor/chemistry form 4/chapter 2 Diffusion in Solid: Test tube is filled with a hot jelly and copper(ii) sulphate crystal. Difussion Rate: Reason: Diffusion in Liquid: A beaker is filled with water & potassium manganate (VII). Difussion Rate: Reason: Diffusion in Gas: A gas jar is filled with few drop of bromine liquid. Difussion Rate: Reason: 7

10 mohd faisol mansor/chemistry form 4/chapter 2 States Particles Arrangement Forces between particles Particles Motion SOLID Held together very strong Vibrate and rotate at fixed position Packed closely in orderly manner LIQUID Packed closely not in orderly arrangement Strong but weaker than solid Vibrate, rotate and move through liquid & collide against each other GAS weak Vibrate, rotate and move freely Far apart from each other Solid Liquid Gas Shape : Shape : Shape : Ability to be compressed: Ability to be compressed: Ability to be compressed: 8

11 mohd faisol mansor/chemistry form 4/chapter 2 Change in the State of Matter Changes in the Heat Energy 9

12 mohd faisol mansor/chemistry form 4/chapter 2 Heating of Naphthalene Cooling of Naphthalene 1. Why is solid naphthalene, C10H8 not heated directly with Bunsen burner? 2. Why is water bath used to heat the naphthalene? 3. During the cooling of naphthalene, explain why a) the boiling tube must place in a conical flask? b) the naphthalene must stirred continuously? 4. What happens to the temperature of naphthalene during a) melting? Give a reason. b) freezing? Give a reason. 5. The melting point of sugar is 184 o C. The melting point of sugar cannot be determined using same apparatus. Why? What apparatus can be used instead? 10

13 mohd faisol mansor/chemistry form 4/chapter 2 The Heating Curve of Naphthalene Temperature ( o C) D B C A Time (min) Melting Point Is the temperature at which a solid changes into a liquid at a particular pressure. Physical State AB = BC = CD = Why the temperature increase from A to B? When solid is heated, heat energy is. This cause particles to kinetic energy and vibrate. Why the temperature remains constant at BC? Heat energy by the particles is used to overcome the force between the particles so that the solid turn into liquid. Also known as latent heat of fusion. Why the temperature increase from C to D? When liquid is heated, heat energy is. This cause particles to kinetic energy and move. * label the melting point of the naphthalene in the diagram above as MP. 11

14 mohd faisol mansor/chemistry form 4/chapter 2 The Cooling Curve of Naphthalene Temperature ( o C) E F G H Time (min) Freezing Point Is the temperature at which a liquid changes into a solid at a particular pressure. Physical State EF = FG = GH = Why the temperature decrease from E to F? When liquid is cooled, heat energy is. This cause particles to kinetic energy and move. Why the temperature remains constant at FG? Heat energy to the surroundings is exactly same as the heat energy released by particle to form the forces to become a solid. How to avoid supercooling? Why the temperature decrease from G to H? When solid is cooled, heat energy is. This cause particles to kinetic energy and vibrate. * label the freezing point of the naphthalene in the diagram above as FP. 12

15 mohd faisol mansor/chemistry form 4/chapter 2 The Atomic Structure [Draw the atomic model & briefly explain] (1) John Dalton ( ) (2) J.J. Thomson ( ) (3) Ernest Rutherford ( ) (5) James Chadwick ( ) (4) Neils Bohr ( ) 13

16 mohd faisol mansor/chemistry form 4/chapter 2 Subatomic Particles of an Atom NEUTRON PROTON Symbol : p Relative electric charge : +1 Relative mass: 1 Symbol : n Relative electric charge : 0 Relative mass: 1 ELECTRON Symbol : e NUCLEUS Proton + Neutron Relative electric charge : -1 Relative mass: NUCLEON NUMBER = Proton + Number of Number Neutron Atom Q has a proton number of 11 and a nucleon number of 23. How many protons, electrons and neutrons are present in the atom? NEUTRAL ATOM Number of proton is equal to the number of electron. Definition Nucleon number is the total number of proton and neutrons in its atom. Definition Proton number is the number of protons in its atom. 14

17 mohd faisol mansor/chemistry form 4/chapter 2 Symbol of Elements Element Symbol Element Symbol Element Symbol Element Symbol Hydrogen Carbon Sodium Sulphur Helium Nitrogen Magnesium Chlorine Lithium Oxygen Aluminium Argon Beryllium Fluorine Silicon Potassium Boron Neon Phosphorus Calcium Na Also represented by sodium-23 A fluorine atom has 9 protons and 10 neutrons. What is the proton number and nucleon number of the atom? Represent the atom in the form of. Bromine-80 has 45 neutrons. What are the proton number and nucleon number of the atom? Represent the atom in the form of. 15

18 mohd faisol mansor/chemistry form 4/chapter 2 ISOTOPES Atoms of the same element has same proton number but different number of neutron Why isotopes element has similar chemical properties? Element Nucleon Number Proton Number Hydrogen-1 1 Hydrogen-2 Hydrogen-3 No. of Neutron No. of Electron Carbon-12 6 Carbon-13 Carbon-14 Oxygen-16 8 Oxygen-17 Oxygen-18 Chlorine Chlorine-37 Bromine Bromine-81 To determine the rate of absorption of fertilisers by plants. USES OF ISOTOPES To determine the age of artifact. To detect leaks in underground petroleum pipe. To detect the location of a tumor in the brain. To treat cancer. 16

19 mohd faisol mansor/chemistry form 4/chapter 2 The Electronic Structure of an Atom Maximum number of electron filled in the shell: 1 st = 2 electrons 2 nd = 8 electrons 3 rd = 8 electrons 4 th = 8 electrons Valence Electrons Electrons in the outermost occupied shell. For atoms with more than 20 electrons, the third shell can filled up to 18 electrons. Electron Configuration Chlorine has proton number 17. The last shell filled with electrons known as the outermost occupied shell. Write the electron arrangement for potassium & state the valence electrons. 17

20 mohd faisol mansor/chemistry form 4/chapter 2 Element Proton Number Number of Electron Electron Configuration & Valence Electron Electronic Structure Hydrogen 1 E.C = V.E = Helium 2 Lithium 3 Beryllium 4 Boron 5 Carbon 6 Nitrogen 7 18

21 mohd faisol mansor/chemistry form 4/chapter 2 Element Proton Number Number of Electron Electron Configuration & Valence Electron Electronic Structure Oxygen 8 Fluorine 9 Neon 10 Sodium 11 Magnesium 12 Aluminium 13 19

22 mohd faisol mansor/chemistry form 4/chapter 2 Element Proton Number Number of Electron Electron Configuration & Valence Electron Electronic Structure Silicon 14 Phosphorus 15 Sulphur 16 Chlorine 17 Argon 18 20

23 mohd faisol mansor/chemistry form 4/chapter 2 Element Proton Number Number of Electron Electron Configuration & Valence Electron Electronic Structure Potassium 19 Calcium 20 21

24 mohd faisol mansor/chemistry form 4/chapter 3 CHAPTER 3 CHEMICAL FORMULAE & EQUATIONS Relative Atomic Mass Average mass of one atom of an element 1/12 x mass of an atom of carbon-12 Relative Molecular Mass Average mass of one molecule 1/12 x mass of an atom of carbon-12 Relative Formula Mass Average mass of one formula unit 1/12 x mass of an atom of carbon-12 Example 1) Element mercury is 20 times heavier than helium. Determine the relative atomic mass of element mercury if the relative atomic mass of helium is 4. 2) The relative atomic mass of helium, nitrogen and sulphur is 4, 14, and 32 respectively. a) How many times is one atom of sulphur heavier than one atom of helium. b) Calculate the number of atoms of helium that have the same mass as two atoms of nitrogen. Relative Molecular Mass (RMM)/Relative Formula Mass (RFM) can be calculated by adding up the Relative Atomic Mass (RAM). + - RMM = Water, H2O RFM = Sodium Chloride, NaCl 22

25 mohd faisol mansor/chemistry form 4/chapter 3 Example Atom, Molecule & Ion 1. Calculate relative molecular mass of the following element or compound. a) Oxygen gas, O2 b) Chlorine gas, Cl2 c) Carbon dioxide, CO2 d) Ammonia, NH3 e) Iodine gas, I2 f) Sulphur dioxide, SO2 g) Sugar, C6H12O6 h) Ethanol, C2H6O 2. Calculate relative formula mass of the following compound. a) Magnesium oxide, MgO b) Potassium iodide, KI c) Calcium carbonate, CaCO3 d) Copper(II) nitrate, Cu(NO3)2 e) Aluminium oxide, Al2O3 f) Zinc Sulphate, ZnSO4 g) Hydrated magnesium sulphate, MgSO4.7H2O h) Hydrated copper(ii) sulphate, CuSO4.5H2O 23

26 mohd faisol mansor/chemistry form 4/chapter 3 The Mole, Number of Particles, Mass & Volume of Substances. NUMBER OF PARTICLES One mole of substance contains 6.02 x particles. MASS OF SUBSTANCES The mass of one mole of the substance equal to the mass of 6.02 x particles. Avogadro Constant NA = 6.02 x mole = no of particles NA No of particles = mole x NA MOLE Amount of substance that contains as many particles as the number of atoms in exactly 12 g of carbon-12 Molar Mass = RAM/RMM/RFM mole = Mass Molar Mass Mass = mole x MM VOLUME OF GAS One mole of any gas always has the same volume under the same temperature & pressure. Unit conversion 1 dm 3 = 1000 cm 3 Molar Volume 1) Room Condition = 24 dm 3 mol -1 2) At S.T.P = 22.4 dm 3 mol -1 mole = Volume Molar Volume Volume = mole x MV 24

27 mohd faisol mansor/chemistry form 4/chapter 3 Example 1 1. A closed glass bottle contains 0.5 mol of oxygen gas, O2. a) How many oxygen molecules, O2 are there in the bottle? b) How many oxygen atoms are there in the bottle? 2. Find the number of moles of hydrogen gas, H2 containing a) 3.01 x hydrogen molecule, H2 b) 6.02 x hydrogen atoms. 3. Find the number of moles of molecules in a sample containing 9.03 x molecules of carbon dioxide, CO2. 4. A sample contains 6.02 x molecule of water. How many moles of water are there in the sample? 25

28 mohd faisol mansor/chemistry form 4/chapter 3 5. A container contains x oxygen molecules, O2. A sample of 0.5 mol of oxygen gas, O2 is added to the container. How many molecules are there altogether in the container? 6. Calcium is needed for the formation of bones and teeth. How many calcium ions are there in a serving of cereal that contains mol of calcium ions? 7. A beaker contains 0.1 mol of zinc chloride, ZnCl2 a) Calculate the number of moles of chloride ions in the beaker. b) Find the total number of ions in the beaker. 26

29 mohd faisol mansor/chemistry form 4/chapter 3 Example 2 1. What is the mass of a) 0.1 mol of magnesium? [RAM: Mg, 24] b) x atoms of magnesium? [RAM: Mg, 24 ; NA = 6.02 x ] 2. How many moles of molecules are there in 16 g of sulphur dioxide gas, SO2? [RAM: O, 16 ; S, 32] 3. How many chloride ions are there in 27.2 g of zinc chloride, ZnCl2? [RAM: Cl, 35.5 ; Zn, 65 ; NA = 6.02 x ] 27

30 mohd faisol mansor/chemistry form 4/chapter 3 4. What is the mass of carbon that contains 6.02 x carbon atoms? 5. What is the mass of a) 0.01 mol of ammonia gas, NH3? b) 6.02 x nitrogen molecules, N2? 6. How many moles of molecules are there in 2.8 g of carbon monoxide, CO? 28

31 mohd faisol mansor/chemistry form 4/chapter 3 Example 3 1. What is the volume of 1.2 mol of ammonia gas, NH3 at STP? [Molar volume: 22.4 dm 3 mol -1 ] 2. How many moles of ammonia gas, NH3 are present in 600 cm 3 of the gas measured at room conditions? [molar volume: 24 dm 3 mol -1 ] 3. Calculate the volume of the following gases. a) 0.3 mol of oxygen gas, O2, at room condition. b) 4 mol of helium gas measured at STP. 4. Calculate the number of moles of 48 dm 3 of chlorine gas, Cl2, at room condition. 29

32 mohd faisol mansor/chemistry form 4/chapter 3 Example 4 1. What is the volume of 12.8 g of oxygen gas, O2, in cm 3, at STP? [RAM: O, 16 ; Molar volume: 22.4 dm 3 mol -1 ] 2. How many molecules of carbon dioxide, CO2, are produced when 120 cm 3 of the gas is released during chemical reaction between an acid and a carbonate at room conditions? [Molar volume: 24 dm 3 mol -1 ; NA = 6.02 x ] 3. What is the mass of 0.6 dm 3 of chlorine gas, Cl2 at room condition? [RAM: Cl, 35.5 ; Molar volume = 24 dm 3 mol -1 ] 4. 3 dm 3 of an unknown gas has a mass of 6.0 g at room conditions. Find the molar mass of the gas. 30

33 mohd faisol mansor/chemistry form 4/chapter 3 CHEMICAL FORMULAE A representation of a chemical substance using letters and subscript numbers. Magnesium Nitrate Water Mg(NO3)2 H2O [state the number of particles consist in the substance above] Empirical Formula The simplest number ratio of atoms in the compound. Compound Water Molecular Formula H2O Empirical Formula Ethene CH2 2 Glucose C6H12O6 n Molecular Formula = (Empirical Formula)n Molecular Formula The actual number of atoms that are present in the compound. RMM of Molecular Formula RMM of Empirical Formula = n The empirical formula of a compound is CH2. Its relative molecular mass is 42. Find its molecular formula. [RAM: H, 1 ; C, 12] Copper(II) Oxide Magnesium Oxide 31

34 mohd faisol mansor/chemistry form 4/chapter 3 To determine Empirical Formulae of Magnesium Oxide 1. Why is the magnesium ribbon cleaned with sand paper before used? 2. Name the white fumes produced. 3. State the reason: a) covering the crucible with its lid as soon as the magnesium start burning. b) raising the lid of the crucible at intervals during heating. c) heating, cooling & weighing are repeated until constant mass is obtained. 4. Why is it important not to let any white fumes escape from the crucible? To determine Empirical Formulae of Copper(II) Oxide 1. Why do we start off with copper(ii) oxide instead of allowing copper to react with oxygen in the air in this experiment? 2. How do you test that the air in the tube has been removed completely? 3. Explain what will happen if we burn excess hydrogen gas without removing the air completely in combustion tube? 4. Why we need to continue the flow of hydrogen gas after the heating of copper(ii) oxide? 5. Why do we need to repeat heating, cooling and weighing until constant mass is obtained? 32

35 mohd faisol mansor/chemistry form 4/chapter 3 Example 1 a) A sample of aluminium oxide contains 1.08 g of aluminium and 0.96 g of oxygen. What is the empirical formula of this compound? [RAM: O, 16 ; Al, 27] Element Al O Mass of Element (g) Number of Mole Ratio of Mole Simplest Ratio Empirical Formula of Aluminium Oxide = b) 0.20 g of calcium reacts with fluorine to give 0.39 g of calcium fluoride. Find the empirical formula of the calcium fluoride produced. [RAM: F, 19 ; Ca, 40] 33

36 mohd faisol mansor/chemistry form 4/chapter 3 c) Find the empirical formula of a compound that consists of 32.4% of sodium, 22.6% of sulphur and 45.0% of oxygen. [RAM: O, 16, Na, 23 ; S, 32] d) 60 g of aluminium sulphide contains 38.4 g of sulphur. Find the empirical formula of the compound. [RAM: Al, 27 ; S, 32] 34

37 mohd faisol mansor/chemistry form 4/chapter 3 Example 2 a) Butane has empirical formula of C2H5 and relative molecular mass of 58. Find its molecular formula. b) Ethanoic acid is an important ingredient of vinegar. The empirical formula of this acid is CH2O. Given that its molar mass is 60 g mol -1, find its molecular formula. c) 6.24 g of element X combines with 1.28 g of oxygen to produce a compound with an empirical formula of X2O. What is relative atomic mass of X? [RAM: O, 16] 35

38 mohd faisol mansor/chemistry form 4/chapter 3 d) Element Y react with oxygen to produce a compound with molecular formula YO3. Given that the mass of 1 mol of the compound is 80 g. Determine the relative atomic mass of element Y. e) Determine the percentage composition by mass of water in hydrated copper(ii) sulphate, CuSO4.5H2O. [RAM: H, 1 ; O, 16 ; S, 32 ; Cu, 64] f) Due to its high nitrogen content, urea, CO(NH2)2 is commercially used as fertilizers. Calculate the percentage composition by mass of nitrogen in urea, CO(NH2)2. [RAM: H, 1 ; C, 12 ; N, 14 ;O, 16] 36

39 mohd faisol mansor/chemistry form 4/chapter 3 Metal Atom Cation (+ve ion) IONIC COMPOUND Ionic Formulae Nonmetal Atom Anion (-ve ion) Zinc Zn Oxygen O Zn 2+ O 2- Zinc Oxide ZnO Ionic Formulae Silver Silver Chloride Ionic Formulae Chlorine 37

40 mohd faisol mansor/chemistry form 4/chapter 3 Charge Name of Cation Formula of Cation Hydrogen ion H + Lithium ion Li Sodium ion Na + Potassium ion K + Silver ion Ag + Ammonium ion NH4 + Barium ion Ba 2+ Calcium ion Ca 2+ Magnesium ion Mg 2+ Zinc ion Zn 2+ Copper(II) ion Cu 2+ Iron(II) ion Fe 2+ Lead(II) ion Pb 2+ Aluminium ion Al 3+ Iron(III) ion Fe 3+ Charge Name of Anion Formula of Anion Hydroxide ion OH - Chloride ion Cl Fluoride ion F - Bromide ion Br - Iodide ion I - Nitrate ion NO3 - Oxide ion O 2- Sulphate ion SO4 2- Carbonate ion CO Phosphate ion PO4 3-38

41 mohd faisol mansor/chemistry form 4/chapter 3 Name of Cation Hydrogen ion Formula of Cation Name of Cation Hydrogen ion Formula of Cation Lithium ion Magnesium ion Sodium ion Barium ion Potassium ion Potassium ion Silver ion Iron(II) ion Ammonium ion Ammonium ion Barium ion Zinc ion Calcium ion Aluminium ion Magnesium ion Lithium ion Zinc ion Iron(III) ion Copper(II) ion Sodium ion Iron(II) ion Calcium ion Lead(II) ion Silver ion Aluminium ion Copper(II) ion Iron(III) ion Lead(II) ion Name of Anion Hydroxide ion Formula of Anion Name of Anion Phosphate ion Formula of Anion Chloride ion Bromide ion Fluoride ion Oxide ion Bromide ion Carbonate ion Iodide ion Iodide ion Nitrate ion Chloride ion Oxide ion Sulphate ion Sulphate ion Nitrate ion Carbonate ion Hydroxide ion Phosphate ion Fluoride ion 39

42 mohd faisol mansor/chemistry form 4/chapter 3 Name of Cation Hydrogen ion Formula of Cation Name of Cation Hydrogen ion Formula of Cation Lithium ion Lithium ion Sodium ion Sodium ion Potassium ion Potassium ion Silver ion Silver ion Ammonium ion Ammonium ion Barium ion Barium ion Calcium ion Calcium ion Magnesium ion Magnesium ion Zinc ion Zinc ion Copper(II) ion Copper(II) ion Iron(II) ion Iron(II) ion Lead(II) ion Aluminium ion Aluminium ion Iron(III) ion Iron(III) ion Lead(II) ion Name of Anion Hydroxide ion Formula of Anion Name of Anion Hydroxide ion Formula of Anion Chloride ion Chloride ion Fluoride ion Fluoride ion Bromide ion Bromide ion Iodide ion Iodide ion Nitrate ion Nitrate ion Oxide ion Oxide ion Sulphate ion Sulphate ion Carbonate ion Carbonate ion Phosphate ion Phosphate ion 40

43 mohd faisol mansor/chemistry form 4/chapter 3 Name of Cation Hydrogen ion Formula of Cation Name of Cation Hydrogen ion Formula of Cation Lithium ion Lithium ion Sodium ion Sodium ion Potassium ion Potassium ion Silver ion Silver ion Ammonium ion Ammonium ion Barium ion Barium ion Calcium ion Calcium ion Magnesium ion Magnesium ion Zinc ion Zinc ion Copper(II) ion Copper(II) ion Iron(II) ion Iron(II) ion Lead(II) ion Aluminium ion Aluminium ion Iron(III) ion Iron(III) ion Lead(II) ion Name of Anion Hydroxide ion Formula of Anion Name of Anion Hydroxide ion Formula of Anion Chloride ion Chloride ion Fluoride ion Fluoride ion Bromide ion Bromide ion Iodide ion Iodide ion Nitrate ion Nitrate ion Oxide ion Oxide ion Sulphate ion Sulphate ion Carbonate ion Carbonate ion Phosphate ion Phosphate ion 41

44 mohd faisol mansor/chemistry form 4/chapter 3 Example Construct the chemical formula for each of the following ionic compound. a)magnesium hydroxide b) Silver iodide c) Potassium Bromide d) Zinc nitrate e) Sodium carbonate f) Aluminium oxide g) Copper(II) iodide h) Iron(II) sulphate i) Magnesium oxide j)calcium carbonate l) Ammonium phosphate m) Sodium hydroxide n) Zinc bromide o) Lead(II) nitrate p) copper(ii) sulphate 42

45 mohd faisol mansor/chemistry form 4/chapter 3 Example 1. Write the formula of the following substances. a) Potassium iodide = b) Magnesium oxide = c) Carbon dioxide = d) Copper(II) oxide = e) Lead(II) bromide = f) Calcium chloride = g) Hydrochloric acid = h) Copper(II) sulphate = i) Hydrogen gas = j) Water = k) Sulphuric acid = l) Silver chloride = m) Potassium nitrate = n) Calcium carbonate = o) Aluminium oxide = p) Oxygen gas = q) Oleum = r) Ammonium sulphate = s) Sodium chloride = t) Zinc oxide = 1) Nitric acid = 2) Lead(II) iodide = 3) Copper(II) nitrate = 4) Zinc sulphate = 5) Iron(II) chloride = 6) Iron(III) chloride = 7) Chlorine gas = 8) Potasium nitrate = 9) Silver nitrate = 10) Magnesium bromide = 11) Zinc chloride = 12) Sodium hydroxide = 13) Ammonia = 14) Iron(II) sulphate = 15) Lead(II) oxide = 16) Carbon monoxide = 17) Magnesium sulphate = 18) Ammonium nitrate = 19) Potassium hydroxide = 20) Lithium oxide = 43

46 mohd faisol mansor/chemistry form 4/chapter 3 Example 1. Write the formula of the following substances. a) Potassium iodide = b) Magnesium oxide = c) Carbon dioxide = d) Copper(II) oxide = e) Lead(II) bromide = f) Calcium chloride = g) Hydrochloric acid = h) Copper(II) sulphate = i) Hydrogen gas = j) Water = k) Sulphuric acid = l) Silver chloride = m) Potassium nitrate = n) Calcium carbonate = o) Aluminium oxide = p) Oxygen gas = q) Oleum = r) Ammonium sulphate = s) Sodium chloride = t) Zinc oxide = 1) Nitric acid = 2) Lead(II) iodide = 3) Copper(II) nitrate = 4) Zinc sulphate = 5) Iron(II) chloride = 6) Iron(III) chloride = 7) Chlorine gas = 8) Potasium nitrate = 9) Silver nitrate = 10) Magnesium bromide = 11) Zinc chloride = 12) Sodium hydroxide = 13) Ammonia = 14) Iron(II) sulphate = 15) Lead(II) oxide = 16) Carbon monoxide = 17) Magnesium sulphate = 18) Ammonium nitrate = 19) Potassium hydroxide = 20) Lithium oxide = 44

47 mohd faisol mansor/chemistry form 4/chapter 3 Example 1. Write the formula of the following substances. a) Potassium iodide = b) Magnesium oxide = c) Carbon dioxide = d) Copper(II) oxide = e) Lead(II) bromide = f) Calcium chloride = g) Hydrochloric acid = h) Copper(II) sulphate = i) Hydrogen gas = j) Water = k) Sulphuric acid = l) Silver chloride = m) Potassium nitrate = n) Calcium carbonate = o) Aluminium oxide = p) Oxygen gas = q) Oleum = r) Ammonium sulphate = s) Sodium chloride = t) Zinc oxide = 1) Nitric acid = 2) Lead(II) iodide = 3) Copper(II) nitrate = 4) Zinc sulphate = 5) Iron(II) chloride = 6) Iron(III) chloride = 7) Chlorine gas = 8) Potasium nitrate = 9) Silver nitrate = 10) Magnesium bromide = 11) Zinc chloride = 12) Sodium hydroxide = 13) Ammonia = 14) Iron(II) sulphate = 15) Lead(II) oxide = 16) Carbon monoxide = 17) Magnesium sulphate = 18) Ammonium nitrate = 19) Potassium hydroxide = 20) Lithium oxide = 45

48 mohd faisol mansor/chemistry form 4/chapter 3 Example Name the following ionic compound by using their IUPAC name. Ionic Formula Name Ionic Formula Name NaCl KI MgO BaSO4 Cu(NO3)2 CaCO3 Al2O3 FeCl3 ZnCl2 LiOH CuO FeSO4 AgNO3 NaOH MgBr2 ZnO PbSO4 PbI2 NaBr Na + Sodium Br - Bromide Sodium Bromide 46

49 mohd faisol mansor/chemistry form 4/chapter 3 a) Qualitative Aspect CHEMICAL EQUATIONS K(S) + H2O(l) KOH(aq) + H2(g) Reactant Product Meaning: Solid Potassium react with water liquid to give potassium hydroxide solution and hydrogen gas p/s: 1) Able to classify reactant and product. 2) Able to balance the equation. Example 1 For each equation, identify the reactant(s), product(s) and the state of each of them. Then, balance the equation. a) H2 (g) + O2 (g) H2O (l) b) CuO (s) + HCl (aq) CuCl2 (aq) + H2O (l) c) Cl2 (g) + NaBr (aq) NaCl (aq) + Br2 (l) d) Mg (s) + HCl (aq) MgCl2 (aq) + H2 (g) 47

50 mohd faisol mansor/chemistry form 4/chapter 3 Example 2 Write a balanced equation for each of the following reactions. a) Carbon monoxide gas + oxygen gas Carbon dioxide gas b) Hydrogen gas + nitrogen gas Ammonia gas c) Aluminium + iron(iii) oxide Aluminium oxide + iron d) Ammonia gas react with oxygen gas to yield nitrogen monoxide gas and water. e) Silver nitrate solution is added to calcium chloride solution. Silver chloride precipitate and calcium nitrate solution are produced. f) When solid zinc carbonate is heated, it decomposes into zinc oxide powder and carbon dioxide gas. 48

51 mohd faisol mansor/chemistry form 4/chapter 3 Example 3 1. Construct balanced chemical equations: a) Magnesium react with oxygen will produce magnesium oxide. b) Sodium metal react with chlorine gas will produce sodium chloride. c) Potassium oxide react with water will produce potassium hydroxide. d) Lithium metal react with water will produce lithium hydroxide and hydrogen gas. e) Zinc metal react with water will produce zinc oxide and hydrogen gas. f) Calcium carbonate react with hydrochloric acid will produce calcium chloride, water and carbon dioxide. g) Hydrochloric acid react with sodium hydroxide will produce sodium chloride and water. h) Potassium oxide react with nitric acid will produce potassium nitrate and water. 49

52 mohd faisol mansor/chemistry form 4/chapter 3 i) Iron metal react with chlorine gas will produce iron(iii) chloride. j) Magnesium metal react with nitric acid with produce magnesium nitrate and hydrogen gas. k) Zinc metal dissolved in copper(ii) chloride will produce zinc chloride and copper metal. l) Chlorine gas react with potassium bromide will produce potassium chloride and bromine gas. m)copper(ii) carbonate when heated will produce copper(ii) oxide and carbon dioxide. n) Lead(II) nitrate when heated will produce lead(ii) oxide, nitrogen gas and oxygen gas. o) Potassium iodide react with lead(ii) nitrate will produce lead(ii) iodide and potassium nitrate solution. p) Sodium hydroxide react ammonium chloride will produce sodium chloride, water and ammonia gas. q) Zinc metal react with hydrochloric acid will produce zinc chloride and hydrogen gas. r) Magnesium oxide react with sulphuric acid will produce magnesium sulphate react with water. 50

53 mohd faisol mansor/chemistry form 4/chapter 3 b) Quantitative Aspect 2H2 (g) + O2 (g) 2H2O(l) 2 molecule Or 2 mol 1 molecule Or 1 mol 2 molecule Or 2 mol Note: The coefficient in the reaction tell the exact proportions of reactant and product in chemical reaction. Example 1. Copper(II) oxide, CuO reacts with aluminium according to the following equation. 3CuO (s) + 2Al (s) Al2O3 (s) + 3Cu (s) Calculate the mass of aluminium required to react completely with 12 g of copper(ii) oxide, CuO. [RAM: O, 16 ; Al, 27 ; Cu, 64] 51

54 mohd faisol mansor/chemistry form 4/chapter 3 2. A student heats 20 g of calcium carbonate, CaCO3 strongly. It decomposes according to the equation below. CaCO3 (s) CaO (s) + CO2 (g) a) If the carbon dioxide produced is collected at room conditions, what is its volume? b) Calculate the mass of calcium oxide, CaO produced. [RAM: C, 12 ; O, 16 ; Ca, 40 ; Molar volume = 24 dm 3 mol -1 ] 52

55 mohd faisol mansor/chemistry form 4/chapter 3 3. Hydrogen peroxide, H2O2 decomposes according to the following equation. 2H2O2 (l) 2H2O (l) + O2 (g) Calculate the volume of oxygen gas, O2 measured at STP that can obtained from the decomposition of 34 g of hydrogen peroxide. [RAM : H, 1 ; O, 16 ; Molar volume = 22.4 dm 3 mol -1 ] g of copper(ii) oxide, CuO is reacted with excess methane, CH4. Using the equation below, find the mass of copper that is produced. 4CuO (s) + CH4 (g) 4Cu (s) + CO2 (g) + 2H2O (l) [RAM : H, 1 ; C, 12 ; O, 16 ; Cu, 64] 53

56 mohd faisol mansor/chemistry form 4/chapter 4 CHAPTER 4 PERIODIC TABLE OF ELEMENTS 54

57 mohd faisol mansor/chemistry form 4/chapter 4 PERIODIC TABLE 55

58 mohd faisol mansor/chemistry form 4/chapter 4 Historical Development of Periodic Table Antoine Lavoiser ( ) first scientist classify substances. Johann Dobereiner ( ) divided element according their similar chemical properties John Newlands ( ) arranged element in order of increasing atomic mass Lothar Meyer ( ) showing that the properties of the elements formed a periodic pattern against their atomic masses. Dmitri Mendeleev ( ) arranged the elements in order of increasing atomic mass and grouped them according to similar chemical properties. Henry J.G. Moseley ( ) Studied the X-ray spectrum of elements. He rearranged the elements in order of increasing proton number. Concluded that the proton number should be the basis for the periodic change of chemical properties instead of the atomic mass. Leading to the modern Periodic Table. 56

59 mohd faisol mansor/chemistry form 4/chapter 4 Arrangement of Element in the Periodic Table Element in the Periodic Table are arranged in an increasing order of proton number ranging 1 to 118. Element with similar chemical properties are placed in the same vertical column 18 vertical column called a group 7 horizontal rows called a period GROUP The number of valence electron in an atom decides the position of the group of an element. GROUP Valence electron 1 and 2 GROUP Valence electron 3 until 8 PERIOD Equal to the number of shell occupied with electrons in its atom Example: An atom of element X has a proton number of 15. In which group and period we can find element X in Periodic Table. 57

60 mohd faisol mansor/chemistry form 4/chapter 4 Exercise Atom, Molecule & Ion 1. Element D has a proton number 19. Where is element D located in Periodic Table? 2. An atom of element E has 10 neutrons. The nucleon number of element E is 19. In which group and period of element E located in the Periodic Table? 3. An atom of element G has 3 shell occupied with electrons. It is placed in Group 17 of the Periodic Table. What is the electron arrangement of atom G? 4. An atom Y is located in Group 18 and period 2 of the periodic Table. What is the electron arrangement and proton number of atom Y? 5. Element R has a proton number of 11. Its atom has 6 neutrons. In which group and period can you find element R in the Periodic Table? 58

61 mohd faisol mansor/chemistry form 4/chapter 4 The advantage of grouping elements in the Periodic Table 1. Helps us to study the element systematically especially their physical and chemical properties. 2. Element with a same number valence electron is place in the same group because they have the same chemical properties. 3. It could be used to predict undiscovered properties. 4. To relate the characteristic of an element with atomic structure 59

62 mohd faisol mansor/chemistry form 4/chapter 4 GROUP 18 consist of helium, neon, argon, krypton, xenon and radon GROUP 18 Known as NOBLE GAS Exist as monoatomic gas. Physical Properties of Group 18 COLOUR SOLUBILITY ELECTRIC CONDUCTIVITY GROUP 18 NOBLE GAS DENSITY MELTING & BOILING POINT 60

63 mohd faisol mansor/chemistry form 4/chapter 4 The inert properties of G18 All noble gas are inert which means unreactive. Noble gas are inert because the outermost occupied shell are full. This electron arrangements are very stable. Helium have 2 valence electron, this electron arrangement is called duplet electron arrangement whereas other noble gas have eight valence electron which called octet electron arrangement. p/s: All other element try to achieve noble gas electron arrangement to become stable. The Physical Properties of G18 The physical properties vary down the group. physical properties vary down the group are related to atomic size. Melting and boiling point of an element increase when going down the group because the atomic sizes increase, the forces attraction (Van der Waals forces) becomes stronger. Thus more heat energy is required to overcome the forces. The strength of Van der Waals forces propotional to the size of particle 61

64 mohd faisol mansor/chemistry form 4/chapter 4 Uses of Noble Gas Elements [ State the element of group 18 ] Fill light bulb laser for repair retina, photographic flash lamps treatment cancer fill airships and weather balloons Car bulb, use in bubble chamber advertising light and television tubes 62

65 mohd faisol mansor/chemistry form 4/chapter 4 Exercise 1. Table below shows the electron arrangements of atoms of elements P, Q, and R. Element Electron Arrangement P 2.8 Q R a) Arrange the element in ascending order of boiling points. Give reasons for your answer. b) Elements P, Q, and R are chemically unreactive. Why? 2) What is the meaning of a) Duplet electron arrangement b) Octet electron arrangement 63

66 mohd faisol mansor/chemistry form 4/chapter 4 GROUP 1 Known as Alkali Metals. Have valence electron of 1. Consist of elements such as lithium, sodium, potassium, rubidium, caesium and francium. Physical Properties of Group 1 HARDNESS APPEARANCE ELECTRIC CONDUCTIVITY GROUP 1 ALKALI METALS DENSITY MELTING POINT 64

67 mohd faisol mansor/chemistry form 4/chapter 4 Element Atomic Size Melting / Boiling point Density Hardness Lithium Sodium Potassium Rubidium Caesium Francium A melting point of a metal indicates the strength of its metallic bonding in its structure. Generally, the strength of metallic bonding is directly proportional to the number of valence electron per atom divided by the radius of a metal. A metallic bond can be defined as the electrostatic force between the positively charged metallic ions and the sea of electrons. Electropositivity is the measurement of an atom to release an electron and form positive ion When going down the group, what happen to the electropositivity of the element? Why? 65

68 mohd faisol mansor/chemistry form 4/chapter 4 Chemical Properties of Group 1 Elements React vigorously with water to produce alkaline metal hydroxide solution and hydrogen gas, H2. 2Li (s) + 2H2O 2LiOH (aq) + H2 (g) Burn in oxygen gas rapidly to produce solid metal oxide 4Li (s) + O2 (g) 2 Li2O (s) Solid metal oxide dissolve in water to form alkaline metal hydroxide Li2O (s) + H2O 2LiOH (aq) Alkaline metal burn in chlorine gas, Cl2 to form white solid metal chloride 2Na (s) + Cl2 2NaCl (aq) Exercise : 1. Why does Group 1 element have similar chemical properties? 2. Why is paraffin oil used to store metals such as sodium and potassium? 3. Element in Group 1 has similar chemical properties but differ in reactivity. Why? 66

69 mohd faisol mansor/chemistry form 4/chapter 4 To investigate the chemical properties of Lithium, Sodium & Potassium 1) The reaction of alkali metals with water 2) The reaction of alkali metals with O2 gas [ Draw the diagram ] [ Draw the diagram ] [ Discussion ] 1. Why are the experiments involving sodium and potassium demonstrated by your teacher and not carried out by the students? 2. Write the chemical equations for the reactions of lithium, sodium and potassium with a) Water, H2O Lithium : Sodium : Potassium : b) Oxygen gas, O2 Lithium : Sodium : Potassium : 67

70 mohd faisol mansor/chemistry form 4/chapter 4 3. Write the chemical equations for the reactions between the products from the combustion of each alkali metal with water. Lithium : Sodium : Potassium : Exercise 1. A student performs two experiments to study the reaction of alkali metal with water. Experiment Metal used Observation 1 Sodium Sodium moves rapidly and randomly on the water surface and emits hiss sounds. 2 Lithium Lithium moves slowly on the water surface. a) Write the chemical equation for the reaction between sodium and lithium with water. Lithium : Sodium : b) Between reactions of Experiment 1 and 2, which is more vigorous? Explain your answer from the point of electron arrangement. c) Explain why sodium and lithium show similar chemical properties? d) Calculate the volume of hydrogen gas produced if 2.3 g of sodium is used. [RAM: Na, 23 ; molar volume: 24 dm 3 mol -1 ] 68

71 mohd faisol mansor/chemistry form 4/chapter 4 GROUP 17 consist of fluorine, chlorine, bromine, iodine and astatine. GROUP 17 Known as HALOGENS. Have valence electron of 7. GROUP 17 Elements are poisonous. Exist as diatomic molecules. Element Symbol of Atom Symbol of Molecule Physical state at room condition Colour Fluorine Chlorine Bromine Iodine Astatine Melting & Boiling Point Electric Conductivity Density Physical State HALOGENS Smell 69

72 mohd faisol mansor/chemistry form 4/chapter 4 Element Atomic Size Melting / Boiling point Density Electronegativity Fluorine Chlorine Bromine Iodine Astatine Electronegativity is an ability of atom to receive an electron to become negative charged ions. All halogen have seven valence electron. Their atoms always gain one electron to form an ion with a charge of 1, in order to achieve stable octet electron arrangement. Chemical Properties of Group 17 Elements Halogen react with water to produce two acids Cl2 + H2O HCl + HOCl Halogen react with metal to produce metal halides 2Fe (s) + 3Cl2 (g) FeCl3 (s) Halogen react with sodium hydroxide solution to form sodium halide and sodium halate (I) and water I2(s) + 2NaOH (aq) NaI (aq) + NaOI (aq) + H2O (l) 70

73 mohd faisol mansor/chemistry form 4/chapter 4 [Draw the Apparatus] To Investigate the Chemical Properties of Halogens SECTION A : Reaction with Water 1) Chlorine 2) Bromine 3) Iodine SECTION B : Reaction with Iron 1) Chlorine 2) Bromine 3) Iodine SECTION C : Reaction with Sodium Hydroxide 1) Chlorine 2) Bromine 3) Iodine 71

74 mohd faisol mansor/chemistry form 4/chapter 4 [Discussion] 1. Name the products formed when chlorine, bromine, and iodine react with water. Chlorine : Bromine : Iodine : 2. Write the chemical equations for the reaction of chlorine, bromine and iodine with water. Chlorine : Bromine : Iodine : 3. What is the function of soda lime in SECTION B? 4. Name the products formed when chlorine, bromine, and iodine react with iron. Chlorine : Bromine : Iodine : 5. Write the chemical equation for the reaction of chlorine, bromine, and iodine with iron. Chlorine : Bromine : Iodine : 72

75 mohd faisol mansor/chemistry form 4/chapter 4 4. Name the products formed when chlorine, bromine, and iodine react with sodium hydroxide solution. Chlorine : Bromine : Iodine : 5. Write the chemical equation for the reaction of chlorine, bromine, and iodine with sodium hydroxide solution. Chlorine : Bromine : Iodine : 6. Describe the changes in reactivity of Group 17 elements when going down the group. Explain your answer. 73

76 mohd faisol mansor/chemistry form 4/chapter 4 Exercise 1. Table below shows several halogen elements with their proton numbers. Halogen Proton Number X 9 Y 17 Z 35 a) State the group that the halogen elements belong to in the Periodic Table. b) i) Write the electron arrangement of elements X and Y. ii) From your answers in (b)(i), deduce the period of elements X and Y. c) Draw the electron arrangement of element Y. d) State the changes of properties of halogens down the group from X to Z in terms of: i) Atomic radius ii) Electronegativity iii) Melting point and boiling point 74

77 mohd faisol mansor/chemistry form 4/chapter 4 e) i) Iron glow brightly when reacting with element Y. Write the chemical reaction to represent this reaction. ii) Predict the observation for the reaction between iron and element Z. iii) Between Y and Z, which is more reactive? Explain why. f) i) Determine the elements X, Y and Z. ii) State the colour for each elements X, Y, and Z. iii) Why the physical state of halogen differ when down the group? 75

78 mohd faisol mansor/chemistry form 4/chapter 4 Comparison & Similarities between Group 1 and Group 17 Properties Group Down the Group Atomic Size Melting & Boiling Point Density Reactivity

79 mohd faisol mansor/chemistry form 4/chapter 4 Elements in a Period 3 Element Sodium Magnesium Aluminium Silicon Phosphorus Sulphur Chlorine Argon Symbol Proton Number Electron Arrangement Metal Properties Physical State [RC] Atomic Radius Electronegativity Property of the oxide The proton number by one unit. All atom of the element have shells occupied by electron. The number of valence electron from 1 to 8. All element exist as except chlorine and argon. The atomic radius of element. The electronegativity of element. The oxides of element in Period 3 change from basic to acidic properties, therefore the metallic properties decrease across the period. On the other hand non-metallic properties of the elements increase. Note: the atomic radius and electro negativity due to the increasing nuclei attraction on the valence electrons. (nuclei attraction force increase with the increase of proton number) 77

80 mohd faisol mansor/chemistry form 4/chapter 4 Transition Elements Transition elements are elements from Group 3 to Group 12 All the elements are metals, usually solids with shiny surfaces, ductile, malleable and have tensile strength. Have high melting and boiling point as well as high density. Good conductors of heat and electricity. Three special characteristics of transition element Show different oxidation number in their compound. Form coloured ions or compound. Act as catalysts. 78

81 mohd faisol mansor/chemistry form 4/chapter 5 CHAPTER 5 CHEMICAL BONDS Almost all chemical substances exist as compounds in nature except inert gases and other stable element (such as gold and silver). Atom of other element that have less than eight valence electron are not stable Less stable atom will tend to release, accept or share electron to achieve the stable electron arrangement All other elements combine together to achieve the stability by forming duplet or octet electron arrangement by i) The transfer of electron ii) Sharing of electron Two types of chemical bonds formed:- i) ionic bonds ii) covalent bond Ionic Bond Covalent Bond 79

82 mohd faisol mansor/chemistry form 4/chapter 5 Ionic Bond Ionic bond formed when metal atom transfer electrons to non-metal atom to form ionic compound. Formation of Cation Formation of Anion Example: Draw the formation of sodium ion. Metal atom from group 1,2 and 13 tend to released all their valence electrons. Non-Metal atom from group 15, 16 and 17 tend to accept the electrons. 80

83 mohd faisol mansor/chemistry form 4/chapter 5 Exercise 1. Draw the formation of the following cations: a) Potassium ion b) Magnesium ion c) Aluminium ion 81

84 mohd faisol mansor/chemistry form 4/chapter 5 2. Draw the formation of the following anions: a) Chloride ion b) Oxide ion c) Nitride ion 82

85 mohd faisol mansor/chemistry form 4/chapter 5 Formation of Ionic Compound 1. Metal atom and non-metal atom are not stables. 2. To achieve stability, metal atom will combine with non- metal atom by transfer of electrons. 3. Metal atoms will donate electrons to form cation. X X + + e 4. Non-metal atom will accept electrons to form anion. Y + e Y - 5. Both ions already achieve stable duplet/octet electron arrangement. 6. The formation of cation & anion will create strong electrostatic force between the ions. 7. Ionic bond will pull cation & anion together in crystal lattice form. 8. The compound formed called as ionic compound. Example: Formation of Sodium Chloride, NaCl 83

86 mohd faisol mansor/chemistry form 4/chapter 5 Exercise 1. Explain the formation of ionic compound below: a) Lithium fluoride b) Magnesium oxide 84

87 mohd faisol mansor/chemistry form 4/chapter 5 c) Calcium chloride d) Aluminium oxide 85

88 mohd faisol mansor/chemistry form 4/chapter 5 2. Draw the formation of the following ionic compound: a) Lithium fluoride b) Magnesium oxide 86

89 mohd faisol mansor/chemistry form 4/chapter 5 c) Calcium chloride d) Aluminium oxide 87

90 mohd faisol mansor/chemistry form 4/chapter 5 Ionic Equations Equation that represent the formation of ionic compounds are known as ionic equation. Example: a) Formation of sodium chloride, NaCl i) Chemical Equation : ii) Half-ionic Equation : b) Formation of Magnesium oxide, MgO i) Chemical Equation : ii) Half-ionic Equation : Exercise 1. Write an ionic equation of the following compound a) Lithium fluoride b) Magnesium chloride c) Aluminium oxide 88

91 mohd faisol mansor/chemistry form 4/chapter 5 Exercise 1. Atom X and Y each have proton numbers of 3 and 8. What is the ionic compound formula formed between atoms X and Y? 2. Complete each of the following table: Atom Proton Number Electron Arrangement Ionic Formula Atom Proton Number Electron Arrangement Ionic Formula Compound Formula A 3 B 9 1 C 11 D 8 2 E 12 F 17 3 G 20 H 9 4 I 19 J 17 5 K 13 L 8 6 M 13 N 17 89

92 mohd faisol mansor/chemistry form 4/chapter 5 Covalent Bond Covalent bond is the chemical bond formed through the sharing of electron between two or more non metal atom to form covalent compound. Three types of covalent bonds: single covalent bond ( sharing one pair of e ) double covalent bond ( sharing two pairs of e ) triple covalent bond ( sharing three pairs of e ) Single Covalent Bond Example: Draw the formation of chlorine gas. 90

93 mohd faisol mansor/chemistry form 4/chapter 5 Double Covalent Bond Example: Draw the formation of oxygen gas. Triple Covalent Bond Example: Draw the formation of nitrogen gas. 91

94 mohd faisol mansor/chemistry form 4/chapter 5 Exercise 1. Draw the formation of the following compound. a) water b) Carbon dioxide 92

95 mohd faisol mansor/chemistry form 4/chapter 5 c) Ammonia b) Tetrachloromethane, CCl4. 93

96 mohd faisol mansor/chemistry form 4/chapter 5 Determine the Formula of Covalent Compound Guideline: 1. State the electron configuration of atoms. - Make sure electron valence for both atoms is either 4, 5, 6, and Determine the number of electrons needed to achieve stability. 3. Write the number of electron needed to achieve stability at the below right corner of each atom. 4. Cross the number. Example: If atom P has 8 protons and atom Q has 9 protons, determine the formula of the covalent compound formed. 94

97 mohd faisol mansor/chemistry form 4/chapter 5 Exercise 1. Atoms K and S each have a proton number of 6 and 8 respectively. What is the formula of the covalent compound which is formed by K and S? 2. Complete the table below to show the formulae of compounds which are formed. Atom Proton number Electron config. Atom Proton number Electron config. Compound formula A B AB4 C 6 D 16 E 7 F 1 G 1 H 8 I 6 J 17 K 6 L 8 95

98 mohd faisol mansor/chemistry form 4/chapter 5 Comparison between the formation of the ionic bond and the covalent bond IONIC BOND COVALENT BOND Similarity Differences Formation Particles Force of Attraction 96

99 mohd faisol mansor/chemistry form 4/chapter 5 The following figure compares and contrasts the properties of ionic compound and covalent compound IONIC COMPOUND COVALENT COMPOUND PROPERTIES Melting & Boiling point Electric Conductivity Physical State Solubility 97

100 mohd faisol mansor/chemistry form 4/chapter 5 Exercise 1. (a) Table 1.1 shows the proton number of three elements, X, Y, and Z. The letters used do not represent the actual symbols of the elements. Element Proton Number X 6 Y 12 Z 17 Table 1.1 i) Write the electron arrangement of: Atom Y : The ion of Z : ii) Write the formula of the compound formed between elements Y and Z. iii) Element X reacts with element Z to form a covalent compound with a formula XZ4. State two physical properties of this compound. i) Draw the electronic structure of the compound XZ4. 98

101 mohd faisol mansor/chemistry form 4/chapter 5 (b) Table 1.2 shows some physical properties of two compounds, U and V. Compound Melting pt ( o C) Boiling pt ( o C) Solubility in water Solubility in organic solvent U Soluble Insoluble V Insoluble Soluble Table 1.2 i) State the physical state of the following compound at room condition. U : V : ii) State the type of compound for U. iii) Explain why melting point and boiling point of compound U is higher than V? 99

102 mohd faisol mansor/chemistry form 4/chapter 6 CHAPTER 6 ELECTROCHEMISTRY Electrolytes are substances that can conduct electricity when they are in molten state and aqueous solution. This due to the present of free moving ions in the electrolytes. Electrolysis is a process whereby compounds in molten or aqueous state are broken down into their constituent elements by passing electricity through them. Non-electrolytes are substances that can not conduct electricity when they are in all state. This because non-electrolyte exist as molecule which means contain no ions. Example 2NaCl (l) 2Na (s) + Cl2 (g) Sodium Metal Chlorine Gas 100

103 mohd faisol mansor/chemistry form 4/chapter 6 Electrolytic Cell (molten state) [ Draw the apparatus of electrolysis molten sodium chloride ] a) Electrode attach to positive terminal (battery) = b) Electrode attach to negative terminal (battery) = c) Anion (negative ion) discharged at electrode = Anion will electrons. d) Cation (positive ion) discharged at electrode = Cation will electrons. e) Electron flow from to f) Electrolytic Cell will change the energy to energy. 101

104 mohd faisol mansor/chemistry form 4/chapter 6 Product of Electrolysis Ion discharged at Cathode All ion metal except Copper ion Observation Half-equation Product Copper ion Hydrogen ion Ion discharged at Anode Observation Half-equation Product Oxide ion Chloride ion Bromide ion Iodide ion Hydroxide ion Hydrogen gas Gas Test Oxygen gas Chlorine gas 102

105 mohd faisol mansor/chemistry form 4/chapter 6 Electrolysis Molten Lead(II) Bromide P Q 1. State the ion consists in the electrolyte. 2. Which electrode is a) Cathode = b) Anode = 3. Which ion will be discharged at a) Cathode = b) Anode = 4. State the observation at a) Cathode = b) Anode = 5. State the product formed at a) Cathode = b) Anode = 6. Write the half equation at a) Cathode = b) Anode = 7. Draw the electron flow on the diagram above. 103

106 mohd faisol mansor/chemistry form 4/chapter 6 Exercise 1. State the ion present in the following electrolyte. Predict the products from the electrolysis of some molten compound and write the ionic equation involved. a) Magnesium oxide b) Copper(II) chloride c) Lead(II) iodide 104

107 mohd faisol mansor/chemistry form 4/chapter 6 2. State the meaning of the following terms. a) Anode b) Cathode c) Electrolysis 3. A molten oxide, R2O3 is electrolysed using carbon electrodes. a) Draw a labeled diagram to show the set-up of apparatus for the electrolysis. b) What ions are present in the electrolyte? Write the formulae for the ions present in the electrolyte. c) State the ions move to each of the electrodes during electrolysis. 105

108 mohd faisol mansor/chemistry form 4/chapter 6 d) Write half equation of the reaction at each of the electrodes. e) Name the substances formed at each of the electrodes. f) Label the flow of electron in the diagram (a). 106

109 mohd faisol mansor/chemistry form 4/chapter 6 107

110 mohd faisol mansor/chemistry form 4/chapter 6 Electrolysis of Aqueous Solution Aqueous solution consists of four types of ions. Two ions from the compound and two ions from the water. Example: Molten sodium chloride Sodium chloride solution Generally, there are 3 factors that may influence the selective of ions during electrolysis of an aqueous solution 1. Position of ions in the electrochemical series 2. Concentration of ions in the electrolytes 3. Types of electrodes used in the electrolysis 108

111 mohd faisol mansor/chemistry form 4/chapter 6 Position of ions in the electrochemical series (ECS) The ions that are lower in the ECS will selected to be discharged. [ Draw the apparatus of electrolysis sodium chloride solution ] 1. State the ion consists in the electrolyte. 2. Which electrode is a) Cathode = b) Anode = 3. Which ion will be discharged at a) Cathode = b) Anode = 4. State the observation at a) Cathode = b) Anode = 5. State the product formed at a) Cathode = b) Anode = 6. Write the half equation at a) Cathode = b) Anode = 7. Draw the electron flow on the diagram above. 109

112 mohd faisol mansor/chemistry form 4/chapter 6 Exercise 1. Carbon electrode Copper(II) sulphate solution For the electrolysis of copper(ii) sulphate solution, (a) State all the ions that are present in the electrolyte. (b) State the ions in (a) which discharged to the i) anode : ii) cathode : (c) Write a half equation for the reaction at the i) anode : ii) cathode : (d) The blue colour of copper(ii) sulphate solution fades if the electrolysis is carried for a long period of time. Explain why. 110

113 mohd faisol mansor/chemistry form 4/chapter 6 2. Carbon electrode Dilute sulphuric acid For the electrolysis of dilute sulphuric acid, a) State all the ions that are present in the electrolyte b) State the ion in (a) which discharged to i) anode ii) cathode c) Write half equation for the reaction at the i) anode ii) cathode d) Explain why the concentration of dilute sulphuric acid increases gradually during the electrolysis 3. Base on the answer 1(c) and 2(c), name the process that occur at the a) anode b) cathode 111

114 mohd faisol mansor/chemistry form 4/chapter 6 Concentration of ions in the electrolytes If the concentrations of particular ions are high, the ion is selectively discharged [ Draw the apparatus of electrolysis concentrated sodium chloride solution ] 1. State the ion consists in the electrolyte. 2. Which electrode is a) Cathode = b) Anode = 3. Which ion will be discharged at a) Cathode = b) Anode = 4. State the observation at a) Cathode = b) Anode = 5. State the product formed at a) Cathode = b) Anode = 6. Write the half equation at a) Cathode = b) Anode = 7. Draw the electron flow on the diagram above. 112

115 mohd faisol mansor/chemistry form 4/chapter 6 Exercise 1. Carbon electrode Dilute Hydrochloric acid solution Experiment A Carbon electrode Concentrated Hydrochloric acid Experiment B Diagram above show the apparatus set up for the experiments of electrolysis using two different concentration of hydrochloric acid. a) State all the ions that are present in the electrolyte i) Experiment A : ii) Experiment B : 113

116 mohd faisol mansor/chemistry form 4/chapter 6 b) State the ion in (a) which discharged to anode and cathode in i) Experiment A : ii) Experiment B : c) Write half equation for the reaction at the anode and cathode in i) Experiment A : ii) Experiment B : d) State the observation occur at cathode and anode in i) Experiment A : ii) Experiment B : e) State the product formed at cathode and anode in i) Experiment A : ii) Experiment B : 114

117 mohd faisol mansor/chemistry form 4/chapter 6 Types of electrodes used in the electrolysis If using the active electrode at anode, ions that are present in the electrolytes are not discharge. Instead the active electrode will corrodes and dissolves in the electrolytes. [ Draw the apparatus of electrolysis silver chloride solution using silver electrodes ] 1. State the ion consists in the electrolyte. 2. Which electrode is a) Cathode = b) Anode = 3. Which ion will be discharged at a) Cathode = b) Anode = 4. State the observation at a) Cathode = b) Anode = 5. State the product formed at a) Cathode = b) Anode = 6. Write the half equation at a) Cathode = b) Anode = 7. Draw the electron flow on the diagram above. 115

118 mohd faisol mansor/chemistry form 4/chapter 6 Exercise 1. Carbon electrode Copper(II) sulphate solution Experiment A Copper plate Copper(II) sulphate solution Experiment B Diagram above show the apparatus set up for the experiments of electrolysis using two different electrodes immersed in copper(ii) sulphate solution. a) State all the ions that are present in the electrolyte i) Experiment A : ii) Experiment B : 116

119 mohd faisol mansor/chemistry form 4/chapter 6 b) State the observation occur at anode and cathode in i) Experiment A : ii) Experiment B : c) Write half equation for the reaction at the anode and cathode in i) Experiment A : ii) Experiment B : d) Explain the observation on the colour of copper(ii) sulphate solution in i) Experiment A : ii) Experiment B : 117

120 mohd faisol mansor/chemistry form 4/chapter 6 Electrolysis in Industry Most common application: i) Extraction of metal 1) Extraction of Metal Extraction of aluminium from aluminium oxide. ii) Purification of metal iii) Electroplating 2) Purification of Metal In purification: The impure metal is made to be the anode The cathode is a thin layer of pure metal Copper nugget 3) Electroplating Electroplating is a process to coat one metal onto another metal. The purposes of electroplating onto metal are:- i) Make it look more attractive ii) more resistant to corrosion In electroplating : object to be electroplated as the cathode anode is the metal used for plating Electrolyte is a solution of the compound of the electroplating 118

121 mohd faisol mansor/chemistry form 4/chapter 6 Extraction of Metal [ Draw the apparatus of electrolysis for extraction of aluminium from aluminium oxide ] 1) Ion present in electrolyte = 2) Ion discharged a) Cathode = b) Anode = 3) Observation a) Cathode = b) Anode = 4) Half equation a) Cathode = b) Anode = 5)Function of cryolite, Na3AlF6 119

122 mohd faisol mansor/chemistry form 4/chapter 6 Purification of Metal [ Draw the apparatus of electrolysis for purification of impure copper ] 1) Ion present in electrolyte = 2) Ion discharged a) Cathode = b) Anode = 3) Observation a) Cathode = b) Anode = 4) Half equation a) Cathode = b) Anode = 5) Colour changes of electrolyte 120

123 mohd faisol mansor/chemistry form 4/chapter 6 Electroplating [ Draw the apparatus of electrolysis to electroplate key by using copper as electrode ] 1) Ion present in electrolyte = 2) Ion discharged a) Cathode = b) Anode = 3) Observation a) Cathode = b) Anode = 4) Half equation a) Cathode = b) Anode = 5) Colour changes of electrolyte 121

124 mohd faisol mansor/chemistry form 4/chapter 6 Voltaic Cells A simple voltaic cell can be made by dipping two different types of metals in an electrolyte Electron flow from one metal to another metal through the connecting wire in the external circuit. More electropositive metal will release electron, thus act as the negative terminal. Less electropositive metal will accept electron and act as the positive terminal. Continuous flow of electron produces an electric current. Simple zinc-copper Voltaic Zinc more reactive than copper Zinc will act as terminal, and copper will act as terminal. Zinc will release electron to form Zn 2+. Half equation: Cu 2+ ions from copper(ii) sulphate solution receive electron to form copper metal. Half equation : Overall equation: The further the distance between the position of two metals is in ECS the bigger the cell voltage. 122

125 mohd faisol mansor/chemistry form 4/chapter 6 Different Types of Voltaic Cells Two types of voltaic cell: 1) Primary cells: non rechargeable cell Example: Daniell cell, dry cells, alkaline cell 2) Secondary cells: rechargeable cells Example: Lead-acid accumulator, Nickel-cadmium Daniell Cell 1 1. Used salt bridge Salt bridge contain inert ions or salt that does not react with electrolyte. Example: 2. Used porous pot Daniell Cell 2 Porous pot has fine pores that allow ions flow through. What is the function of salt bridge and porous pot in Daniell Cell? 123

126 mohd faisol mansor/chemistry form 4/chapter 6 Exercise 1. For the simple voltaic cell that you see at the diagram Mg Cu Magnesium sulphate solution a) State how electricity was produced. b) What are the chemical changes that occur at the magnesium ribbon and the copper plate. c) Write the half equation for the changes that occur at each the electrode. d) What is the direction of electron flow from terminal to another through the external circuit. 124

127 mohd faisol mansor/chemistry form 4/chapter 6 Electrochemical series (ECS) Tendency of metal to release electrons to form ions increases Tendency of cation to receive electrons to form metals increases The electrochemical series (ECS) can be constructed by two method: a) The potential difference (voltage difference) between pairs of metal. b) The ability of metal to displace another metal from its salt solution. 125

128 mohd faisol mansor/chemistry form 4/chapter 6 The potential difference (voltage difference) between pairs of metal. The bigger the voltage value the further apart their position. The metal act as negative terminal is placed at higher position in electrochemical series (ECS). How to determine the positive/negative terminal? Example: The voltaic cells are constructed as shown in the figure. The voltmeter reading of the cell I is 1.1 V while that of cell II is 2.5 V. Q P R P Cell 1 Cell 2 Arrange the metals in descending order in the electrochemical series. 126

129 mohd faisol mansor/chemistry form 4/chapter 6 The ability of metal to displace another metal from its salt solution If the M can displace metal N from an aqueous N salt solution, then: i) Metal M is more electropositive than metal N ii) Metal M is placed at a higher position than metal N in the ECS Example: Zinc and copper(ii) sulphate sulphate solution Observation : Half-equation : The Important of ECS ECS can be used to determine: The terminal of voltaic cell The standard cell voltage The ability of a metal to displace another metal from its salt solution. 127

130 mohd faisol mansor/chemistry form 4/chapter 6 Exercise 1. The diagram shows an electrolytic cell. The left section of the cell (S) is a source of electricity to drive the right section (T) of the cell. Aluminium Zinc Copper Aluminium Sulphate S Zinc Sulphate T Copper(II) Sulphate a) State the change of energy in cell S b) i) For cell S, state the positive terminal of the cell ii) Explain your choice for b(i) c) i) State what has happened at the negative terminal ii) What process has happened in this electrode 128

131 mohd faisol mansor/chemistry form 4/chapter 6 d) Explain why the color of copper(ii) sulphate remain unchanged e) Determine the anode of cell T f) Write down the half equation for the cathode in cell T g) What will happened if the aluminium in cell S is replaced by copper 129

132 mohd faisol mansor/chemistry form 4/chapter 7 CHAPTER 7 ACIDS AND BASES Arrhenius Theory An acid is a chemical compound that produces hydrogen ions, H + or hydroxonium ions H3O + when dissolve in water. A base defined as a chemical substance that can neutralise an acid to produce a salt and water. An alkali is defined as a chemical compound that dissolve in water to produce hydroxide ions, OH -. Example HCl (g) H 2 O H + (aq) + Cl - (aq) NaOH(s) H 2 O Na + (aq) + OH - (aq) The role of water In the presence of water an acid will ionise to form hydrogen ion and alkaline will dissociate into hydroxide ions, OH -. Therefore, water is essential for the formation of hydrogen ions, H + that cause acidity and hydroxide ions, OH - that cause alkalinity. 130

133 mohd faisol mansor/chemistry form 4/chapter 7 BASICITY OF AN ACID Is the number of ionisable hydrogen atoms per molecule of an acid. Monoprotic Acid Acid which produces 1 hydrogen ion when one molecule of an acid ionises in H2O. Diprotic Acid Triprotic Acid Example: a) CH3COOH? (ethanoic acid) = b) H2SO4? (sulphuric acid ) = c) HNO3? (Nitric acid) = d) H3PO4? (Phosphoric acid) = STRENGTH OF ACID & ALKALI 131

134 mohd faisol mansor/chemistry form 4/chapter 7 STRONG ACID WEAK ACID Strong acid will dissociate or ionize completely in water to produce hydrogen, H + ions. Degree of dissociation is higher. Thus, higher concentration of hydrogen ions in aqueous acid solution. Therefore, low ph value of the acid solution. STRONG ALKALI WEAK ALKALI 132

135 mohd faisol mansor/chemistry form 4/chapter 7 PHYSICAL PROPERTIES OF ACID & ALKALI ph Value Conduct electricity Litmus paper ALKALI ph Value Litmus paper ACID Corrosive Taste Taste Corrosive Conduct electricity 133

136 mohd faisol mansor/chemistry form 4/chapter 7 CHEMICAL PROPERTIES OF ACID & ALKALI Acids can react with, i) bases to produce salts and water eg : ii) metal to produce salts and hydrogen gas eg : iii) metal carbonates to produce salts, carbon dioxide and water eg : iv) alkali to produce salts and water (neutralization) eg : Alkali can react with, i) acid to produce salts and water (neutralization) eg : ii) ammonium salt to produce salts, water and ammonia gas eg : 134

137 mohd faisol mansor/chemistry form 4/chapter 7 The concentration of acid and alkali Concentration are measurement of the quantity of solutes dissolved in a quantity of solvent. Grams per dm 3 ( g dm -3 ) Moles per dm 3 ( mol dm -3 ) *known as Molarity Concentration Unit Conversion Grams per dm 3 ( g dm -3 ) molar mass molar mass Moles per dm 3 ( mol dm -3 ) Example 1. The molarity of a bottle of nitric acid, HNO3 solution is 2.0 mol dm -3. What is the concentration of the solution in g dm -3? [RAM: H, 1 ; N, 14 ; O, 16] 135

138 mohd faisol mansor/chemistry form 4/chapter 7 2. Calculate the molarity of a sodium sulphate, Na2SO4 solution with a concentration of 28.4 g dm -3. [RAM: O, 16 ; Na, 23 ; S, 32] Calculating Involving Concentration and Molarity No of mole = Molarity x Volume ( cm3 ) 1000 MV n = g of copper (II) sulphate is dissolved in water to form 500 cm 3 solution. Calculate the concentration of copper (II) sulphate in g dm A 250 cm 3 nitric acid solution contains 0.4 moles. Calculate the molarity of the nitric acid. 136

139 mohd faisol mansor/chemistry form 4/chapter 7 3. What is the mass of sodium carbonate required to dissolve in water to prepare 200 cm 3 solution contains 50 g dm Calculate the number of moles of ammonia in 150 cm 3 of 2 mol dm -3 aqueous ammonia. 5. Calculate the volume in dm 3 of a 0.8 mol dm -3 sulphuric acid that contains 0.2 mol g sodium carbonate powder, Na2CO3 is dissolved in water and made up to 250 cm 3. What is the molarity of the sodium carbonate solution. [RAM: C,12;O,16;Na,23] 137

140 mohd faisol mansor/chemistry form 4/chapter 7 7. Dilute hydrochloric acid used in the school laboratories usually has a concentration of 2.0mol dm -3. Calculate the mass of hydrogen chloride that found in 250 cm 3 of the hydrochloric acid? [RAM : H,1; Cl,35.5] 8. The concentration of a potassium hydroxide solution is 84.0 g dm -3. Calculate the number of moles of potassium hydroxide present in 300 cm 3 of the solution. [RAM: K,39,H,1 O,16] 138

141 mohd faisol mansor/chemistry form 4/chapter 7 9. Calculate the number of moles of hydrogen ions present in 200 cm 3 of 0.5 mol dm -3 sulphuric acid. Preparation of Standard Solution A solution in which its concentration is accurately known is a standard solution. Preparation of a solution by dilution method Adding water to a concentrated solution changes the concentration of the solution but does not change the amount solutes ( number of moles)of solution present in solution. Add water Stock solution Dilute solution Moles of stock solution = moles of dilute solution n1 = n2 M1V1 = M2V2 139

142 mohd faisol mansor/chemistry form 4/chapter 7 Exercise 1. Find the volume of 2.0 mol dm -3 sulphuric acid, H2SO4 needed to prepare 100 cm 3 of 1.0 mol dm -3 sulphuric acid, H2SO4. 2. Calculate the volume of a concentrated solution needed to prepare each of the following dilute solution: a) 50 cm 3 of 0.1 mol dm -3 sodium hydroxide, NaOH solution from 2.0 mol dm -3 sodium hydroxide, NaOH solution. b) 100 cm 3 of 0.5 mol dm -3 potassium manganate(vii), KMnO4 solution from 1.0 mol dm -3 potassium manganate(vii), KMnO4 solution. 140

143 mohd faisol mansor/chemistry form 4/chapter 7 3. Calculate the volume of 2.0 mol dm -3 sulphuric acid, H2SO4 needed to prepare 2.5 dm 3 of 0.5 mol dm -3 of the same acid solution. 4. Calculate the molarity of potassium hydroxide, KOH, solution if 200 cm 3 of 2.0 mol dm -3 potassium hydroxide, KOH, solution is added to 200 cm 3 of water cm 3 of 0.5 mol dm -3 sodium hydroxide, NaOH, solution is diluted with 30 cm 3 of water. Calculate the molarity of the solution produced. 141

144 mohd faisol mansor/chemistry form 4/chapter 7 The ph Values and Molarity As the molarity of an acid increases, the ph value of the acid decreases, however the ph value of an alkali increases when the molarity of the alkali increases. Neutralisation Reaction of an acid and a base that produce salt and water. Acid-base titration Titration is a very useful laboratory technique in which one solution is used to analyse another solution. An acid of known concentration is carefully delivered from burette to completely neutralise a known volume of an alkali in a conical flask. Acid-base indicator is used to detect the end of titration. Eg: methyl orange, phenolphthalein and litmus. The point at which the colour of the solution change is called the end point. Titration using phenolphthalein 142

145 mohd faisol mansor/chemistry form 4/chapter 7 NEUTRALISATION ACID-BASE TITRATION 143

146 mohd faisol mansor/chemistry form 4/chapter 7 Example 1. Write a balanced equation for the neutralization of each of the following: a) Sulphuric acid, H2SO4 and barium hydroxide, Ba(OH)2 solution. b) Nitric acid, HNO3 and calcium hydroxide, Ca(OH)2 solution. c) Ethanoic acid, CH3COOH and potassium hydroxide, KOH solution. Acid-base Indicator Indicator Colour in alkalis Colour in neutral solution Colour in acids Methyl orange phenolphthalein litmus The end-point of neutralisation also can determined by another two method:- i) Measurement of ph values by computer ii) Measurement of electrical conductivity during titration 144

147 mohd faisol mansor/chemistry form 4/chapter 7 Numerical Problem involving Neutralisation Say the balance equation is aa + bb product which, A = acid a = no of mole of acid B = base b = no of mole of base MAVA = a and MBVB = b Therefore MAVA a = MBVB b Exercise 1. In an experiment, 25.0 cm 3 of a sodium hydroxide solution of unknown concentration required cm 3 of 1.0 mol dm -3 sulphuric acid to complete a reaction in titration. Calculate the molarity of sodium hydroxide. 145

148 mohd faisol mansor/chemistry form 4/chapter 7 2. What is the volume of 0.5 mol dm -3 sulphuric acid, H2SO4 needed to neutralize 25.0 cm 3 of 0.8 mol dm -3 ammonia, NH3 solution? 3. A sample of copper(ii) oxide, CuO was found to completely neutralize 100 cm 3 of 0.5 mol dm -3 hydrochloric acid, HCl. Calculate the mass of the sample. [RAM: O, 16 ; Cu, 64] 146

149 mohd faisol mansor/chemistry form 4/chapter 7 4. The volume of 0.15 mol dm -3 sulphuric acid, H2SO4 required to completely neutralize 25.0 cm 3 of potassium hydroxide, KOH solution is 30.5 cm 3. Calculate the molarity of the potassium hydroxide, KOH solution. 5. A student dissolved 3.65 g of hydrogen chloride gas, HCl in water to make 1.0 dm 3 of solution. Calculate the volume of a 0.1 mol dm -3 barium hydroxide, Ba(OH)2 solution required to completely neutralize 25.0 cm 3 of the acid solution. [RAM : H, 1 ; Cl, 35.5] 147

150 mohd faisol mansor/chemistry form 4/chapter 8 CHAPTER 8 SALTS A salt is an ionic substance produced when the hydrogen ion of the acid is replaced by metal ion or an ammonium ion. The salt consists of two parts, cation from base and anion from acid. NaOH (Base) NaCl HCl (Acid) 148

151 mohd faisol mansor/chemistry form 4/chapter 8 Complete the table below. Table of Salts Metal ion Sulphate salt (SO4 2- ) Chloride salt (Cl - ) Nitrate salt (NO3 - ) Carbonate salt (CO3 2- ) K + K2SO4 KCl KNO3 K2CO3 Na + Ca 2+ Mg 2+ Al 3+ Zn 2+ Fe 2+ Sn 2+ Pb 2+ Cu 2+ Ag + NH4 + Ba 2+ Based on the table above, mark the insoluble salt. 149

152 mohd faisol mansor/chemistry form 4/chapter 8 SOLUBLE & INSOLUBLE SALTS SALT SOLUBLE INSOLUBLE K +, Na +, NH4 + All soluble none Nitrate salts (NO3 - ) Chloride salts (Cl - ) Sulphate salts (SO4 2- ) Carbonate salts (CO3 2- ) Oxide salts (O 2- ) Hydroxide salts (OH - ) All nitrate salts All chloride salts All sulphate salts Sodium carbonate, Na2CO3 Potassium carbonate, K2CO3 Ammonium carbonate, (NH4)2CO3 Sodium oxide, Na2O Potassium oxide, K2O Calcium oxide, CaO (slightly soluble) Sodium hydroxide, NaOH Potassium hydroxide, KOH Calcium hydroxide, Ca(OH)2 (slightly soluble) none Lead (II) chloride, PbCl2 Silver chloride, AgCl Mercury chloride, HgCl Lead (II) sulphate Calcium sulphate Barium sulphate All others carbonate salts All oxide salts All hydroxide salts 150

153 mohd faisol mansor/chemistry form 4/chapter 8 Preparation and Purification of Soluble Salts Soluble salt can be prepared by the following ways: 1. Reaction between acid and alkali - preparation for sodium, potassium and ammonium salts only. Eg: HCl(aq) + NaOH(aq) NaCl(aq) + H2O(l) [write the step of preparation of the salts on the diagram] Burette HCl solution NaCl solution Evaporating dish NaOH solution NaCl crystal salt NaCl salt crystal 151

154 mohd faisol mansor/chemistry form 4/chapter 8 Preparation and Purification of Soluble Salts Soluble salt can be prepared by the following ways: 1. Reaction between acid and metal oxide Eg: HNO3(aq) + MgO(s) Mg(NO3)2 (aq) + H2O(l) 2. Reaction between acid and metal Eg: H2SO4(aq) + Zn (s) ZnSO4(aq) + H2 (g) 3. Reaction between acid and metal carbonate Eg: HCl(aq) + CaCO3(s) CaCl2(aq) + CO2(g) + H2O(l) [write the step of preparation of the salts on the diagram] Copper(II) nitrate Solution + excess CuO heat heat Copper(II) nitrate solution Evaporating Dish Copper(II) nitrate solution & crystal salt Cu(NO 3 ) 2 crystal salt 152

155 mohd faisol mansor/chemistry form 4/chapter 8 Crystallization is a process to crystallize the soluble salts. Recrystallization process will carried out in order to get pure and more defined crystal Physical characteristic of crystals Fixed geometrical shapes such as a cuboids, rhombic or prism Flat surface, straight edges and sharp angles. Same shapes for same substance but differ in sizes Fixes angle between two neighbouring surfaces. 153

156 mohd faisol mansor/chemistry form 4/chapter 8 Preparation of insoluble salts An insoluble salt is prepared through precipitation method. Aqueous solution of two soluble salts are mixed to form insoluble and soluble salt: [write the general equation of preparation insoluble salt] The reaction is called double decomposition. Two solutions contain ions that make up the insoluble salts. Eg: Preparation of lead(ii) iodide salt by using lead(ii) nitrate solution and potassium iodide solution. [write the balance chemical equation] Double Decomposition 154

157 mohd faisol mansor/chemistry form 4/chapter 8 Chemical and Ionic Equation Chemical and ionic equation can be written for all reaction That used to prepare salts. Example: Formation of precipitate Barium Sulphate, BaSO4. 1. Chemical Equation: BaCl2 (aq) + Na2SO4 (aq) BaSO4(s) + 2NaCl (aq) 2. Ionic Equation: Ionic equation shows the ions take part in the reaction. Exercise 1. Change each of the following word equations to a balanced chemical equation. a) Sulphuric acid + zinc zinc sulphate + hydrogen gas. b) Silver nitrate + potassium iodide silver iodide + potassium nitrate c) Nitric acid + chromium(iii) hydroxide chromium(iii) nitrate + water 155

158 mohd faisol mansor/chemistry form 4/chapter 8 2. Complete the following equations. a) HCl (aq) + NiO (s) b) HNO3 (aq) + Ca(OH)2 (aq) c) H2SO4 (aq) + MgCO3 (s) 3. Write an ionic equation for each reaction between the following pairs of substances. a) Sulphuric acid, H2SO4 and barium hydroxide, Ba(OH)2 solution b) Ammonium chloride, NH4Cl solution and silver nitrate, AgNO3 solution. c) Lead(II) nitrate, Pb(NO3)2 solution and copper(ii) sulphate, CuSO4 solution. d) Iron(III) oxide, Fe2O3 and hydrochloric acid, HCl. 156

159 mohd faisol mansor/chemistry form 4/chapter 8 Constructing Ionic Equation using the Continuous Variation Method Continuous variation method can be used to construct ionic equation for the formation of insoluble salts. Fixed volume of a reactant A is react with varying volumes of a reactant B to determine the mole ratio of reactant A that react completely with reactant B. If x mol of reactant A with y mole of reactant B, than the empirical formula for insoluble salt is A x B y. Example: 2Fe 3+ (aq) + 3CO3 2- (aq) Fe2(CO3)3 (s) 157

160 mohd faisol mansor/chemistry form 4/chapter 8 158

161 mohd faisol mansor/chemistry form 4/chapter 8 Example cm 3 of 0.2 mol dm -3 X n+ solution reacts completely with 4.0 cm 3 of 0.1 mol dm -3 Y m- solution to form a salt XmYn. Write the ionic equation and hence determine the empirical formula of the salt reaction cm 3 of 0.1 mol dm -3 solution of P x+ ions reacts completely with 9.0 cm 3 of 0.1 mol dm -3 solution of Q y- ions to form a salt PyQx. Write the ionic equation and hence determine the empirical formula of the salt in this reaction. 159

162 mohd faisol mansor/chemistry form 4/chapter 8 Solving Problem Involving Calculation of Quantities of Reactants or Product in Stoichiometric Reactions Since the quantities of chemicals involved in a reaction are in term of moles, the quantities of chemicals (volume, mass and number of particles) must be converted to moles in calculation regarding quantities of reactant and products. Exercise 1. Calculate the number of moles of aluminium sulphate produced by the reaction of 0.2 mole of sulphuric acid with excess aluminium oxide. [0.067 mol] g of sodium hydroxide reacts with excess sulphuric acid. What is the mass of sodium sulphate produces [RAM: H,1 ; O,16 ; Na,23 ; S,32] [ 3.55 g] 160

163 mohd faisol mansor/chemistry form 4/chapter 8 3. What the volume of carbon dioxide gas evolved at s.t.p when 2.1 g of magnesium carbonate reacts with excess nitric acid. [ RAM: C,12;O,16;Mg,24; s.t.p = 22.4 dm 3 ] [ 560 cm 3 ] 4. What is the mass of magnesium required to react with 20 cm 3 of 2.0 mol dm 3 hydrochloric acid to produce 120 cm 3 of hydrogen at temperature? [RAM: Mg,24 ; 1 mol = 24 dm 3 at room temp.] [ 0.12 g] 161

164 mohd faisol mansor/chemistry form 4/chapter 8 Observations on the physical properties of salts Qualitative Analysis of Salts General procedure of qualitative analysis Action of heat on salts Tests for cations and anions Colour & Solubility of the Salt Confirmatory tests for cations and anions GREEN PALE GREEN Iron(II) Sulphate, FeSO 4 Iron(II) Nitrate, Fe(NO 3 ) 2 Iron(II) Chloride, FeCl 2 BROWN YELLOW/BROWN [depend on concentration] Iron(III) Sulphate, Fe 2 (SO 4 ) 3 Iron(III) Nitrate, Fe(NO 3 ) 3 Iron(III) Chloride, FeCl 3 REDDISH-BROWN INSOLUBLE GREEN INSOLUBLE Iron(III) Oxide, Fe 2 O 3 Copper(II) Carbonate, CuCO 3 BLUE BLUE BLACK INSOLUBLE Copper(II) Sulphate, CuSO 4 Copper(II) Nitrate, Cu(NO 3 ) 2 Copper(II) Chloride, CuCl 2 Copper(II) Oxide, CuO 162

165 mohd faisol mansor/chemistry form 4/chapter 8 Colour & Solubility of the Salt WHITE COLOURLESS WHITE INSOLUBLE Potassium Oxide, K 2 O Sodium Oxide, Na 2 O Calcium Oxide, CaO Magnesium Oxide, MgO Aluminium Oxide, Al 2 O 3 WHITE [cold] YELLOW [cold] INSOLUBLE INSOLUBLE YELLOW [hot] BROWN [hot] Zinc Oxide, ZnO Lead(II) Oxide, PbO 163

166 mohd faisol mansor/chemistry form 4/chapter 8 Gas test Oxygen gas hydrogen gas Wooden splinter Oxygen gas, O 2 Hydrogen gas, H 2 Carbon dioxide gas sulphur dioxide gas Carbon dioxide Sulphur dioxide HCl acid HCl acid Sodium Sulphite, Na 2 SO 3 Sodium Carbonate, Na 2 CO 3 Red litmus paper chlorine gas Glass rod dipped into concentrated HCl acid ammonia gas White fumes Chlorine gas, Cl 2 Ammonia gas, NH 3 164

167 mohd faisol mansor/chemistry form 4/chapter 8 Carbonate salts EFFECT OF HEAT ON SALTS Sodium carbonate & potassium carbonate are very stable. They do not decompose on heating. Heating Carbonate Salt Metal Oxide + Carbon dioxide Heating Carbonate salts [ white ] residue [ white ] Salts Chemical Equation 1. Calcium carbonate 2. Magnesium carbonate 3. Aluminium carbonate Heating Carbonate salts [ white ] residue [ yellow hot ] [ white cold ] Salts Chemical Equation 1. Zinc carbonate 165

168 mohd faisol mansor/chemistry form 4/chapter 8 Heating Carbonate Salt Metal Oxide + Carbon dioxide Heating Carbonate salts [ brown ] residue [ brown ] Salts Chemical Equation 1. Iron(III) carbonate Heating Carbonate salts [ green ] residue [ black ] Salts Chemical Equation 1. Copper(II) carbonate Heating Carbonate salts [ white ] Salts residue [ brown hot ] [ yellow cold ] Chemical Equation 1. Lead(II) carbonate 166

169 mohd faisol mansor/chemistry form 4/chapter 8 Carbonate Salt Heating Metal + Carbon dioxide + Oxygen gas Heating Carbonate salts [ white ] residue [ grey ] Salts Chemical Equation 1. Mercury(II) carbonate Heating Carbonate salts [ white ] residue [ shiny grey ] Salts Chemical Equation 1. Silver carbonate Heating Carbonate salts [ white ] residue [ golden yellow ] Salts Chemical Equation 1. Aurum(II) carbonate 167

170 mohd faisol mansor/chemistry form 4/chapter 8 nitrate salts Nitrate Salt Heating Metal Oxide + Oxygen gas + Nitrogen dioxide Heating nitrate salts [ white ] residue [ white ] Salts Chemical Equation 1. Calcium nitrate 2. Magnesium nitrate 3. Aluminium nitrate Heating nitrate salts [ white ] residue [ yellow hot ] [ white cold ] Salts Chemical Equation 1. Zinc nitrate 168

171 mohd faisol mansor/chemistry form 4/chapter 8 Nitrate Salt Heating Metal Oxide + Oxygen gas + Nitrogen dioxide Heating nitrate salts [ brown ] residue [ brown ] Salts Chemical Equation 1. Iron(III) nitrate Heating nitrate salts [ blue ] residue [ black ] Salts Chemical Equation 1. Copper(II) nitrate Heating Salts nitrate salts [ white ] residue [ brown hot ] [ yellow cold ] Chemical Equation 1. Lead(II) nitrate 169

172 mohd faisol mansor/chemistry form 4/chapter 8 Nitrate Salt Heating Metal + Nitrogen dioxide + Oxygen gas Heating nitrate salts [ white ] Salts residue [ grey ] Chemical Equation 1. Mercury(II) nitrate Heating Salts nitrate salts [ white ] residue [ shiny grey ] Chemical Equation 1. Silver nitrate Nitrate Salt Heating Metal nitrite + Oxygen gas Heating nitrate salts [ white ] residue [ white ] Salts Chemical Equation 1. Potassium nitrate 2. Sodium nitrate 170

173 mohd faisol mansor/chemistry form 4/chapter 8 TEST FOR ANIONS Unknown aqueous salt solution Salt needed to be dissolved into water first to produce aqueous salt solution. [ state the procedure ] [ state the procedure ] [ state the procedure ] [ state the procedure ] OBSERVATION OBSERVATION OBSERVATION OBSERVATION [ label the diagram ] [ label the diagram ] [ label the diagram ] [ label the diagram ] Ionic Equation Ionic Equation Ionic Equation Ionic Equation CONCLUSION CONCLUSION CONCLUSION CONCLUSION [ state the anion ] [ state the anion ] [ state the anion ] [ state the anion ] 171

174 mohd faisol mansor/chemistry form 4/chapter 8 TEST FOR CATIONS Unknown aqueous salt solution Add NaOH drop by drop Salt needed to be dissolved into water (soluble salts) or in dilute acid then filtered (insoluble salts) first to produce aqueous salt solution. No precipitate White precipitate Coloured precipitate Green Add NaOH drop by drop until excess Brown Dissolve in excess NaOH Insoluble in excess NaOH Blue * All coloured ions insoluble in excess NaOH 172

175 mohd faisol mansor/chemistry form 4/chapter 8 TEST FOR CATIONS Unknown aqueous salt solution Add NH 3 drop by drop Salt needed to be dissolved into water (soluble salts) or in dilute acid then filtered (insoluble salts) first to produce aqueous salt solution. No precipitate White precipitate Coloured precipitate Green Add NH 3 drop by drop until excess Brown Dissolve in excess NH 3 Insoluble in excess NH 3 Blue Dissolved in excess NH 3 Dark blue solution * Fe 2+ & Fe 3+ ions insoluble in excess NH 3 173

176 mohd faisol mansor/chemistry form 4/chapter 8 Confirmatory Test for Cation Cation Procedure Observation Fe 2+ Fe 3+ Pb 2+ NH 4 + Exercise 1. Identify the aqueous solutions based on the test and observation given. a. Potassium thiocyanate, KSCN, solution is added. b. Potassium iodide, KI, solution is added. c. Ammonia solution, NH3, is added until excess. d. A little hydrochloric acid is added. e. A sulphuric acid, iron(ii) sulphate solution and concentrated sulphuric acid is added. f. Ammonia solution is added until excess. Type Observation Answer Blood red solution formed. Yellow precipitate is formed. Blue precipitate dissolve to form dark blue solution. Effervescene occur and lime water turn into chalky. Brown ring formed. White precipitate dissolved. K 2 CO 3 ZnCl 2 PbCl 2 CuSO 4 NaNO 3 FeCl 3 174

177 mohd faisol mansor/chemistry form 4/chapter 9 CHAPTER 9 MANUFACTURED SUBSTANCES IN INDUSTRY SULPHURIC ACID The Uses of Sulphuric Acid 175

178 mohd faisol mansor/chemistry form 4/chapter 9 [ Cause by ] [ Effect ] POLLUTION of Sulphur DIOXIDE [ Cause by ] Formation of Acid Rain Burning of Sulphur [ Explain the formation of acid rain & write the chemical equation ] Burning of Sulphur Dioxide [ Explain the formation of acid rain & write the chemical equation ] 176

179 mohd faisol mansor/chemistry form 4/chapter 9 Effect of Acid Rain 177

180 mohd faisol mansor/chemistry form 4/chapter 9 Industrial Process in the Manufacture of Sulphuric Acid Contact Process Burn in the air Stage 1 [ write the chemical equation ] Catalyst: Temp. : Pressure: Stage 2 [ write the chemical equation ] Dissolves in concentrated H 2 SO 4 Stage 3 ( i ) [ write the chemical equation ] Dilute with water Stage 3 ( ii ) [ write the chemical equation ] 178

181 mohd faisol mansor/chemistry form 4/chapter 9 AMMONIA [ Label the uses of ammonia ] The Uses of ammonia 179

182 mohd faisol mansor/chemistry form 4/chapter 9 Properties of ammonia Glass rod dipped into concentrated HCl acid White fumes Ammonia gas, NH 3 180

183 mohd faisol mansor/chemistry form 4/chapter 9 Industrial Process in the Manufacture of Ammonia Haber Process 1 part 3 parts Catalyst : Temperature : Pressure : Catalyst chamber The unreacted mixture will flowed back [ Write the balance chemical equation ] Condenser [ state what happen in the condenser ] [ state the final product ] 181

184 mohd faisol mansor/chemistry form 4/chapter 9 Preparation of Ammonium Fertilisers in the laboratory Ammonia fertilizers can be prepared by using neutralization reaction between acid and ammonia solution. Acid + Ammonia Ammonium salts H 2 SO 4 + NH 3 (NH 4 ) 2 SO 4 Eg: Preparation of ammonium sulphate salt Burette H 2 SO 4 acid solution (NH 4 ) 2 SO 4 solution Evaporating dish Ammonia solution (NH 4 ) 2 SO 4 crystal salt (NH 4 ) 2 SO 4 crystal salt 182

185 mohd faisol mansor/chemistry form 4/chapter 9 Alloys Pure metal is soft and not strong. Atom of pure metal have similar shape and size. The particles in pure metal are arranged layer by layer and easily slide along between each other. Physical Properties Of pure metal Ductile [ state the definition of the ductile and draw the particle arrangement ] malleable [ state the definition of the malleable and draw the particle arrangement ] 183

186 mohd faisol mansor/chemistry form 4/chapter 9 alloys Alloy is a mixture of two or more elements which is the major component is pure metals. Foreign elements either metal or non-metal is added into pure metal. The size of foreign elements either smaller or bigger. It will disrupt the orderly arrangement of pure metal. Thus, the properties of pure metals improved. [ draw the particle arrangement of alloy ] Aim of making alloys 184

187 mohd faisol mansor/chemistry form 4/chapter 9 STEEL Uses of Alloys & Their Compositions [ state the components, properties & uses of alloy ] COPPER-NICKEL DURALUMIN Pure metal : 99% Iron Foreign element : 1% Carbon - Strong - Hard - Withstands corrosion - To make bridge, vehicles, building & train tracks BRASS STAINLESS STEEL PEWTER BRONZE 185

188 mohd faisol mansor/chemistry form 4/chapter 9 Synthetic Polymers Polymers are long chains of molecules made from combination of monomers by polymerisation process. Two types of polymer: i) Natural polymer ii) Synthetic polymer Polymer that occurs naturally made by living organisms. Polymer RUBBER Monomer Natural polymers Polymer CELLULOSE Monomer Polymer PROTEIN Monomer Polymer STARCH Monomer Polymer FAT Monomer Amino acid Isoprene 186

189 mohd faisol mansor/chemistry form 4/chapter 9 Polymer that are man-made polymer produced from chemical compound through polymerisation. Two types of polymerisation: i) Addition polymerisation ii) Condensation polymerisation Polymer POLYTHENE Monomer Synthetic polymers Polymer POLYPROPENE Monomer Polymer NYLON Monomer Polymer POLYVINYL CHLORIDE (PVC) Monomer Polymer PERSPEX Monomer 187

190 mohd faisol mansor/chemistry form 4/chapter 9 Glass & ceramics Main component of glass is silica & silicon dioxide, SiO 2. glass Main characteristics 188

191 mohd faisol mansor/chemistry form 4/chapter 9 Type of Glass FUSED SILICA GLASS Method of Productions SODA-LIME GLASS Method of Productions Compositions Compositions Properties - Very high melting point - Not easy to change its shape - Does not easily expand or shrink with changes of temperature - Transparent to ultraviolet ray Uses Properties - Transparent - Low melting point - Easily shaped - Easily broken - Cannot withstand heat & chemical reaction Uses 189

192 mohd faisol mansor/chemistry form 4/chapter 9 Type of Glass BOROSILICATE GLASS Method of Productions LEAD CRYSTAL GLASS Method of Productions Compositions Compositions Properties - Withstand heat & chemical reaction - High melting point - Transparent to light & infrared ray but not to ultraviolet ray - Expand & shrink a little when temperature changes Uses Properties - Very transparent - Shiny - High density Uses 190

193 mohd faisol mansor/chemistry form 4/chapter 9 Made from clay at very high temperature and the main component is silicate. ceramics Common properties 191

194 mohd faisol mansor/chemistry form 4/chapter 9 Uses of ceramics 192

195 mohd faisol mansor/chemistry form 4/chapter 9 Composite Materials Produced from the combination of two or more different compound such as alloys, metals, glass, ceramic & polymers. USES OF COMPOSITE MATERIALS REINFORCED CONCRETE Compositions SUPERCONDUCTOR Compositions Properties Properties Uses Uses 193

196 mohd faisol mansor/chemistry form 4/chapter 9 USES OF COMPOSITE MATERIALS Compositions FIBRE GLASS Compositions FIBRE OPTICS Properties Properties Uses Uses Success is not the key to happiness. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer - 194

197 mohd faisol mansor/chemistry form 4/chapter 9 USES OF COMPOSITE MATERIALS PHOTOCHROMIC GLASS Compositions Compositions CERAMIC GLASS Properties Properties Uses Uses There are no secrets to success. It is the result of preparation, hard work, and learning from failure. - Colin Powell - 195