Symbols. Table 1 A set of common elements, their symbols and physical state
|
|
- Quentin Barrie Holt
- 5 years ago
- Views:
Transcription
1 Symbols Symbols are a kind of shorthand system for writing down elements and compounds. Each element has a particular one or two letter symbol. The first letter of a symbol is always capital, and if there is a second letter, e.g. Mg (magnesium), this is written in lower case. A complete set of symbols is found in a periodic table. The following table lists some common elements, their symbols, and their physical state at room temperature and pressure. Table 1 A set of common elements, their symbols and physical state Element Symbol Physical State Hydrogen H gas Oxygen O gas Chlorine Cl gas Mercury Hg liquid Gold Au solid Silver Ag solid Molecules Atoms of elements usually join up either with atoms of the same element or with atoms of different elements to form molecules. In both cases the atoms are chemically bound together. On the other hand there are elements whose atoms are not found as molecules but as single atoms. These elements are said to be monatomic, e.g. He, helium; Ne, neon; Kr, krypton; Xe, xenon. Elements whose atoms are found joined up in twos as molecules are called diatomic, e.g. Cl 2, chlorine; O 2, oxygen; N 2, nitrogen. Atoms of one element may join up with atoms of another element to form a new substance. These are called compounds. For example, one atom of oxygen binds chemically with two atoms of hydrogen to form a molecule of water. Water is a compound made up of oxygen and hydrogen. Chemical formulae When we are talking about molecules of compounds we do not write symbols for them, but we write chemical formulae. Taking water as an example, since Symbols 1
2 one molecule of water is composed of two atoms of hydrogen and one of oxygen, the chemical formula can be written as H 2 O. When writing a chemical formula, metals and hydrogen are always written before non-metals, e.g. HCl, NaCl, MgO, etc. The chemical formula of a compound gives the ratio of the atoms of the different elements, e.g. NaCl: one atom of sodium : one atom of chlorine MgCl 2 : one atom of magnesium : two atoms of chlorine Not all chemical formulae are so easy. Look at the chemical formulae in the following tables: Note that for aluminium hydroxide the formula is Al(OH) 3 and not AlO 3 H 3. Why is this so question? The answer to this question comes out when we discuss radicals. A radical is a group of atoms that exists in several compounds but does not exist on its own. The next table contains some common radicals. Table 2: Some radicals Groups of atoms present Name of radical Examples of compounds NO 3 Nitrate NaNO 3, Cu(NO 3 ) 2 NO 2 Nitrite NaNO 2, Cu(NO 2 ) 2 CO 3 Carbonate Na 2 CO 3, K 2 CO 3 HCO 3 Hydrogencarbonate NaHCO 3, Mg(HCO 3 ) 2 SO 4 Sulfate CaSO 4, (NH 4 ) 2 SO 4 SO 3 Sulfite MgSO 3, K 2 SO 3 HSO 4 Hydrogensulfate Mg(HSO 4 ) 2, Ca(HSO 4 ) 2 NH 4 Ammonium NH 4 Cl, (NH 4 ) 2 CO 3 OH Hydroxide NaOH, KOH PO 4 Phosphate AlPO 4, Mg 3 (PO 4 ) 2 Cl Chloride NaCl, CuCl 2 S Sulfide ZnS, FeS O Oxide MgO, CO 2 So when we write the chemical formula of a compound that contains radicals we must consider the radical as one entity and not as separate atoms. Symbols 2
3 Note that when looking at the names of compounds there are certain trends in the endings. For example, the ending -ate indicates a radical containing oxygen, e.g. sodium hydrogencarbonate (NaHCO 3 ), magnesium sulfate (MgSO 4 ). The ending -ide indicates the presence of two elements only, e.g. sodium chloride (NaCl), potassium iodide (KI). Valency But how are we going to decide what is the ratio of atoms combined in a compound. This is decided by the valency of an element. For example, hydrogen has a valency of 1; chlorine has a valency of 1 as well. So hydrogen (H) and chlorine (Cl) will combine to form a molecule of hydrogen chloride in a ratio of 1 hydrogen atom : 1 chlorine atom. The chemical formula will therefore be HCl. One has to remember the valencies of the most common elements. A help to remember this is to know which Group in the Periodic table the element is found in. For example, sodium is in Group 1 and has a valency of 1. Magnesium is in Group 2 and has a valency of 2. Aluminium is in Group 3 and has a valency of 3. Carbon is in Group 4 and has a valency of 4. This rule has to be changed a bit when it comes to Groups 5, 6 and 7. For these groups, the valency is equal to the number of electrons required to achieve an outer shell of 8 electrons which is stable. For Group 5 elements, they have 5 outer electrons and hence need 3 to achieve a noble gas configuration, and so their valency is 3. The same is done for Groups 6 and 7, whose elements have valencies of 2 and 1 respectively. For more notes about valency refer to Topic 6. Also, i. there are some elements that have variable valencies, i.e. they may have more than one valency. This is a property of the transition metals, e.g. Copper has can have a valency of either 1 or 2; iron may have a valency of either 2 or 3; ii. even radicals have valencies (see Table 3 below); Symbols 3
4 iii. noble gases, i.e. the elements found in Group 8 or Group O have a valency of 0. Table 3: Valencies of radicals Radical Symbol Valency Hydroxide OH 1 Chloride Cl 1 Nitrate NO 3 1 Hydrogencarbonate HCO 3 1 Hydrogensulfate HSO 4 1 Ammonium NH 4 1 Oxide O 2 Carbonate CO 3 2 Sulfate SO 4 2 The following table summarises the symbols and valencies of common elements. Table 4 Common elements and their valency Elements Valency Hydrogen 1 Sodium 1 Magnesium 2 Calcium 2 Carbon 4 Oxygen 2 Iron 2 or 3 Steps for writing chemical formulae 1. Look at the name of the chemical compound and write the symbols of the elements and/or radicals that make it up. aluminium chloride: aluminium ion, Al 3+ chloride ion, Cl - Symbols 4
5 2. Note the valencies of the atoms and/or radicals making up the compound. Al - valency 3 Cl - valency 1 3. The valencies need to be balanced if they are not balanced already. Al - valency 3: one ion is needed (resulting valency = 3) Cl - valency 1: three ions are needed (resulting valency 1 x 3 = 3) 4. Therefore for every aluminium ion there is, there have to be three chlorine ions. 5. Resulting chemical formula: AlCl 3 Symbols for states of substances A substance can be either a solid, a liquid or a gas. A substance may also be in solution, usually in water. There is a symbol for all these four states. These symbols are usually written in brackets as subscripts after an element or compound. The symbol for solid is (s). The symbol for liquid is (l). The symbol for gas is (g). The symbol for in aqueous solution is (aq). This means that the substance is in solution in water. These symbols are usually used when we are writing chemical equations. Chemical equations Chemical equations represent what happens in chemical reactions. One can also represent what is happening in a chemical reaction by use of word equations, e.g. iron + sulphur iron sulfide On the left hand side of the equation, one writes the reactant/s, i.e. the substances that actively react in the reaction. Symbols 5
6 On the right hand side of the equation, one writes the product/s, i.e. the substances produced as a result of the reaction. The above is called a WORD EQUATION because words are used to show what is happening. A more accurate and scientific way of showing what happens in a chemical reaction, is to use symbols for elements and chemical formulae instead of words. Hence for the reaction above, we can write, Fe + S FeS We can also add the symbols that show the physical state for each substance, Fe(s) + S(s) FeS(s) Now, one must see that the number of atoms of an element (or radical) on the left hand side must equal those on the right hand side. For the above equation, this is so, and hence the chemical equation is all right. But what about the next one? Zn(s) + HCl(aq) ZnCl 2 (aq) + H 2 (g) Note that for Zn, the number of atoms on the left hand side balance those on the right hand side, but not so for Cl and H. For the equation to be balanced, there must be two HCl molecules on the left hand side, and the equation becomes: Zn(s) + 2HCl(aq) ZnCl 2 (aq) + H 2 (g) Note that the 2" is written IN FRONT of the molecule and not anywhere else. REMEMBER THIS! Numbers in chemical formulae and equations: A,B are the elements or radicals and X is a number. Symbols 6
7 A X, B X : means that there are x atoms of A and X of B in a molecule; e.g. Cl 2, O 2, Na 2 O, AlCl 3. (AB) X : means that there x radicals of AB in a molecule, e.g. (NH 4 ) 2 SO 4, Al(OH) 3, Al 2 (CO 3 ) 3. X AB: means that there are X molecules of AB, e.g. 2 NaCl, 3 MgCO 3. NOTE: When balancing chemical equations, sometimes it is easier to multiply the whole equation, rather than have a fraction, e.g. KClO 3 KClO 3 KCl + O 2 is not balanced; KCl / 2 O 2 is balanced but not correct; 2 KClO 3 2 KCl + 3 O 2 is balanced and correct. Calculations from formulae and equations A chemical formula of a compound does not tell you only what types of atoms make up that compound but also the number of atoms present in that compound. For example, a molecule of magnesium chloride, MgCl 2, has one atom of magnesium and two atoms of chlorine chemically combined together. In moles, one mole of magnesium chloride molecules, consists of one mole of magnesium ions and two moles of chloride ions. In grams, the relative molecular mass (RMM) of MgCl 2 is (24+(35.5 x 2) = 95g. Therefore 95g of MgCl 2 contains 24g of Mg combined with 71g of Cl. These ideas can be used to calculate the empirical formula of a compound, i.e. the simplest ratio of atoms present in a molecule. Example: Find the empirical formula of hydrogen peroxide if 0.04g of hydrogen react with 0.64g of oxygen to form hydrogen peroxide. Atoms present: H O Masses given: H g Symbols 7
8 O g To find the empirical formula we have to obtain a ratio of moles. Number of moles of hydrogen in 0.04g:- 1g of hydrogen molecules contains 1 mole of hydrogen atoms 0.04g of hydrogen molecules contains? moles of hydrogen atoms 0.04 x 1 / 1 = 0.04 moles Number of moles of oxygen in 0.64g:- 16g of oxygen molecules contain 1 mole of oxygen molecules 0.64g of oxygen molecules contain? moles of oxygen molecules 0.64 x 1 / 16 = 0.04 moles Therefore the ratio of moles of hydrogen reacting with moles of oxygen to given hydrogen peroxide is 0.04:0.04 or 1:1 Therefore the empirical formula is HO Another way to calculate the empirical formula is shown in the following example. Example: Sodium sulfate has the following composition by mass: Na 32.4%, S 22.5%, and O 45.1%. What is the empirical formula question Na S O % composition Divide by RAM 32.4/ / /16 Relative number of atoms =1.41 =0.70 =2.82 Divide by smallest number 1.41/ / /0.70 =2 =1 =4 Therefore empirical formula is Na 2 SO 4 Symbols 8
9 Note that for the final division answers may not be whole numbers. In this case round them to the nearest whole or half. Calculating the molecular formula from the empirical formula The molecular formula is different from the empirical formula. The latter gives the simplest ratio of atoms present in a molecule whereas the former gives the actual number of atoms present in a molecule. You can obtain the molecular formula if you know both the empirical formula and the RMM. For example, for hydrogen peroxide, the empirical formula is HO. The mass of this empirical formula is (1 + 16) 17. The RMM is 34. Therefore one immediately notes that the RMM is twice the mass of the empirical formula, and so the molecular formula is (OH) x 2, or H 2 O 2. Percentage composition from the chemical formula If the RMM of a compound is taken as 100%, then the relative atomic masses (RAM) of each element can be taken as a percentage of the total RMM. Example: Find the percentage composition by mass of ammonium nitrate. 1. Write down the formula of the compound: NH 4 NO 3 2. Calculate the RMM: 14 + (1 x 4) (16 x 3) = Take the TOTAL RAM of each element: N = 14 (x 2) = 28 O = 16 (x 3) = 48 H = 1 (x 4) = 4 4. Find what percentage of the RMM, each TOTAL RAM is. N = 28/80 x 100 = 35% Symbols 9
10 O = 48/80 x 100 = 60% H = 4/80 x 100 = 5% 5. Check that the percentages total to 100%. NOTE For hydrated compounds, i.e. compounds that have water of crystallisation, e.g. CuSO 4.5H 2 O, the H 2 O is taken as an entity on its own, and not as H and O on their own. E.g. Percentage composition of MgCl 2.6H 2 O RMM = 24 + (35.5 x 2) + (18 x 6) = 203 Mg = 24/203 x 100 = 11.82% Cl = 71/203 x 100 = 34.98% H 2 O = 108/203 x 100 = 53.2% Mass calculations and equations The masses of reactants or products can be calculated using chemical equations. For example, S(s) + O 2 (g) SO 2 (g) The equation indicates that 1 mole of S reacts with 1 mole of O 2 to produce 1 mole of SO 2. We can express this statement in masses. 32g of S (RAM of S) react with 32g (RAM of O x 2 = 16 x 2) of O 2 to produce 64g of SO 2. This idea can be used to work out masses of products or reactants. Example: Symbols 10
11 How much magnesium oxide will be produced when 48g of magnesium are burned in excess of oxygen. (RAM: Mg = 24; O = 16) 2 Mg(s) + O 2 (g) 2 MgO(s) i.e. 2 moles of Mg + 1 mole of O 2 2 moles of MgO 2 x 24 + excess O 2 2 x ( ) 48g + excess O 2 80g Therefore when 48g of Mg react with excess O 2, 80g of MgO are produced. Example: Calculate the mass of zinc required to produce 81g of zinc oxide when heated in excess of oxygen. (RAM: Zn = 65; O = 16) 2 Zn(s) + O 2 (g) 2 ZnO(s) 2 moles of Zn + excess O 2 2 moles ZnO 2 x 65 + excess O 2 2 x (65+16) 130g + excess O 2 162g But we want to find out the mass of Zn required to produce 81g of ZnO and not 162g. Therefore, 162g of ZnO are produced by 130g of Zn 81g of ZnO are produced by? of Zn = 130 x = 65g of Zn Symbols 11
2. Relative molecular mass, M r - The relative molecular mass of a molecule is the average mass of the one molecule when compared with
Chapter 3: Chemical Formulae and Equations 1. Relative atomic mass, A r - The relative atomic mass of an element is the average mass of one atom of an element when compared with mass of an atom of carbon-12
More informationBalancing Equations Notes
. Unit 9 Chemical Equations and Reactions What is a Chemical Equation? A Chemical Equation is a written representation of the process that occurs in a chemical reaction. A chemical equation is written
More information5072 CHEMISTRY (NEW PAPERS WITH SPA) BASIC TECHNIQUES 5067 CHEMISTRY (NEW PAPERS WITH PRACTICAL EXAM) BASIC TECHNIQUES
5072 CHEMISTRY (NEW PAPERS WITH SPA) BASIC TECHNIQUES 5067 CHEMISTRY (NEW PAPERS WITH PRACTICAL EXAM) BASIC TECHNIQUES LEARNING OUTCOMES a) Be able to write formulae of simple compounds b) Be able to write
More informationBalancing Equations Notes
. Unit 6 Chemical Equations and Reactions What is a Chemical Equation? A Chemical Equation is a written representation of the process that occurs in a chemical reaction. A chemical equation is written
More informationBalancing Equations Notes
. Unit 7 Chemical Equations and Reactions What is a Chemical Equation? A is a written representation of the process that occurs in a chemical reaction. A chemical equation is written with the (starting
More informationBalancing Equations Notes
. Unit 9 Chemical Equations and Reactions What is a Chemical Equation? A is a written representation of the process that occurs in a chemical reaction. A chemical equation is written with the (starting
More informationC2.6 Quantitative Chemistry Foundation
C2.6 Quantitative Chemistry Foundation 1. Relative masses Use the periodic table to find the relative masses of the elements below. (Hint: The top number in each element box) Hydrogen Carbon Nitrogen Oxygen
More informationChemistry. Bridging the Gap Summer Homework. Name..
Chemistry Bridging the Gap Summer Homework Name.. Standard Form Number Number in standard form 0.008 8 x 10-3 0.07 7 x 10-2 0.55 5.5 x 10-1 0.000052 0.048 0.0086 0.00086 0.000086 0.0000000001 0.000455
More informationC2.6 Quantitative Chemistry Foundation
C2.6 Quantitative Chemistry Foundation 1. Relative masses Use the periodic table to find the relative masses of the elements below. (Hint: The top number in each element box) Hydrogen Carbon Nitrogen Oxygen
More informationSCH4U Chemistry Review: Fundamentals
SCH4U Chemistry Review: Fundamentals Particle Theory of Matter Matter is anything that has mass and takes up space. Anything around us and in the entire universe can be classified as either matter or energy.
More informationQuestion 8 Chemical properties of metals and nonmetals. 1) magnesium 2) sulfur trioxide 3) iron (II) hydroxide 4) sodium nitrate
Question 8 Chemical properties of metals and nonmetals 1. Calcium oxide doesn t react with 1) NaNO 3 2) HCl 3) CO 2 4) H 2 O 2. Calcium oxide reacts with both of the following 1) SO 2 and O 2 2) H 2 O
More informationTHE ST. MICHAEL SCHOOL THIRD FORM CHEMISTRY MANUAL 3 SYMBOLS AND FORMULAE, CHEMICAL BONDING AND CHEMICAL EQUATIONS
1 THE ST. MICHAEL SCHOOL THIRD FORM CHEMISTRY MANUAL 3 SYMBOLS AND FORMULAE, CHEMICAL BONDING AND CHEMICAL EQUATIONS COMPILED BY G.WALKER, L.WORRELL, T. HARDING REFERENCE BOOKS Anne Tindale Chemistry A
More informationREVIEW OF BASIC CHEMISTRY ANSWER KEY
REVIEW OF BASIC CHEMISTRY ANSWER KEY 1. Name the following elements. Spelling counts: 2. Write the symbols for the following elements. H hydrogen sodium Na S sulphur phosphorus P Cl chlorine fluorine F
More informationESA Study Guide Year 10 Science
Then and now Questions from pages 26, 27 of ESA Study Guide Year 10 Science 1. Which early scientist thought atoms would combine to form new substances? 2. Which New Zealand scientist found that most of
More informationChapter 4 Compounds and Their Bonds. Octet Rule. Metals Form Positive Ions. Ionic and Covalent Bonds. Formation of a Sodium Ion, Na +
Chapter 4 Compounds and Their Bonds Octet Rule 4.1 Octet Rule and Ions An octet Is 8 valence electrons. Is associated with the stability of the noble gases. Helium (He) is stable with 2 valence electrons
More informationCHEMICAL EQUATIONS WHAT BALANCING AN EQUATION MEANS
17 CHEMICAL EQUATIONS WHAT BALANCING AN EQUATION MEANS WHAT IS A CHEMICAL EQUATION? A chemical equation is a way of representing a chemical reaction in symbolic form. For example, when hydrochloric acid
More informationUnit (2) Quantitative Chemistry
Unit (2) Quantitative Chemistry Chapter (1) :The mole & chemical equation Lesson (1) Mole and chemical equation Chemical equation: The chemical symbols and formulas of the reactants and products which
More informationChemical Reactions Unit
Name: Hour: Teacher: ROZEMA / Chemistry Chemical Reactions Unit 1 P a g e 2 P a g e 3 P a g e 4 P a g e 5 P a g e 6 P a g e Chemistry Balancing Equations Balance the following equations by inserting the
More informationCHEMISTRY 135 REVISION OF NAMES, FORMULAE AND EQUATIONS
CHEMISTRY 135 REVISION OF NAMES, FORMULAE AND EQUATIONS Answer the following questions as if you were going to hand them in for marking. You will be tested on them in class time. 1) Give the correct chemical
More informationTHE MOLE - PART 2. Multiple Choice Identify the letter of the choice that best completes the statement or answers the question.
THE MOLE - PART 2 Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. Which one of the following statements is a quantitative observation? a.
More informationUNIT 1 Chemical Reactions Part II Workbook. Name:
UNIT 1 Chemical Reactions Part II Workbook Name: 1 Molar Volume 1. How many moles of a gas will occupy 2.50 L at STP? 2. Calculate the volume that 0.881 mol of gas at STP will occupy. 3. Determine the
More informationRepresenting Chemical Change
Representing Chemical Change As we have already mentioned, a number of changes can occur when elements react with one another. These changes may either be physical or chemical. One way of representing
More informationChemical Reactions. Ch. 11 Chemical Reactions. Chemical Reactions. Chemical Reactions
Chemical Reactions Ch. 11 Chemical Reactions when a substance changes identity Reactants - original Products - resulting law of conservation of mass total mass of reactants = total mass of products In
More informationCHAPTER 9 CHEMICAL QUANTITIES
Chemistry Name Hour Chemistry Approximate Timeline Students are expected to keep up with class work when absent. CHAPTER 9 CHEMICAL QUANTITIES Day Plans for the day Assignment(s) for the day 1 Begin Chapter
More informationChemical Equations. Chemical Reactions. The Hindenburg Reaction 5/25/11
Chemical Reactions CHM 1032C Chemical Equations Chemical change involves a reorganization of the atoms in one or more substances. The Hindenburg Reaction Reactants are on left, products to the right. Arrow
More informationFrom Writing Formulas to Balancing Equations A Tutorial
Chemistry Revised 2013 Name From Writing Formulas to Balancing Equations A Tutorial Period Oxidation Numbers. The Oxidation numbers written as s _ tell whether an element or group of elements lost or gained
More informationReaction Writing Sheet #1 Key
Reaction Writing Sheet #1 Key Write and balance each of the following reactions and indicate the reaction type(s) present: 1. zinc + sulfur zinc sulfide 8 Zn (s) + S 8 (s) 8 ZnS (s) synthesis 2. potassium
More informationBullers Wood School. Chemistry Department. Transition to A Level Chemistry Workbook. June 2018
Bullers Wood School Chemistry Department Transition to A Level Chemistry Workbook June 2018 This booklet contains questions for you to work through and answer over the summer to prepare for the A level
More informationChemical reactions: Chemical reactions change substances into other substances.
Chemical reactions: Chemical reactions change substances into other substances. A chemical equation is used to represent a reaction. This has the form: reactants à products Word equations use the names
More informationComplete this study guide to receive 5 bonus points on your test. Only study guides that are complete will receive the bonus.
CHEMISTRY AND PERIODIC TABLE STUDY GUIDE Assigned: Thursday, 09 10 14 Due: Thursday, 09 18 14 Test Day: Friday, 09 19 14 Complete this study guide to receive 5 bonus points on your test. Only study guides
More information8 Chemical Equations. Flames and sparks result when aluminum foil is dropped into liquid bromine.
8 Chemical Equations Flames and sparks result when aluminum foil is dropped into liquid bromine. Chapter Outline 8.1 The Chemical Equation 8.2 Writing and Balancing Chemical Equations 8.3 Types of Chemical
More informationStoichiometry Dry Lab
Stoichiometry Dry Lab Name: Mole-Mass Conversions The molar mass of a substance is the conversion factor that allows us to convert between the mass of a substance (in grams) and the number of moles of
More informationChemical Reactions and Equations
Chemical Reactions and Equations 5-1 5.1 What is a Chemical Reaction? A chemical reaction is a chemical change. A chemical reaction occurs when one or more substances is converted into one or more new
More informationThe Masses of chemicals
The Masses of chemicals Boardworks Ltd 2003 WILF To give a definition of relative formula mass M r. To calculate relative formula mass if its formula and the relative atomic mass are given. To give a full
More informationCHAPTER 11 Stoichiometry Defining Stoichiometry
CHAPTER 11 Stoichiometry 11.1 Defining Stoichiometry Stoichiometry is the study of quantitative relationships between amounts of reactants used and products formed by a chemical reaction. Stoichiometry
More information9. The ratio of the volume of nitrogen to that of the ammonia in the reaction N2 + 3 H2 2 NH3 is 1) 1:2; 2) 1:3; 3) 3:2; 4) 2:3.
1. In a balanced chemical equation l) coefficients are equal; 2) atoms are conserved; 3) molecules are equal; 4) energy is always produced; 5) none of these. 2. Which of the following statements about
More informationScience 1206 Ch. 3 - Chemical names, formulas and equations
Science 1206 Ch. 3 - Chemical names, formulas and equations 3.1 - Ionic and molecular compounds (pp. 98-107) Compounds A compound is a pure substance made of a combination of elements. The elements are
More informationWhat Do You Think? Investigate GOALS
Cool Chemistry Show Activity 4 Chemical Equations GOALS In this activity you will: Represent chemical changes using word equations and chemical equations. Distinguish between different classes of chemical
More informationChemical Bonds In elements and compounds, the atoms are held together by chemical bonds.
Chemical Bonds In elements and compounds, the atoms are held together by chemical bonds. Forming a bond makes an atom more stable, so atoms form as many bonds are they are able to. Bonds are made using
More information1. What is a dot diagram? 2. Drawing dot diagrams. Name:
Name: Skill Sheet 29.2 Dot Diagrams You have learned that atoms are composed of protons, neutrons, electrons. The electrons occupy energy levels that surround the nucleus in the form of an electron cloud.
More informationIdentify the reaction type, predict the products, and balance the equations. If it is a special decomposition or synthesis, identify which kind.
Identify the reaction type, predict the products, and balance the equations. If it is a special decomposition or synthesis, identify which kind. 1. calcium + oxygen 2. cupric carbonate 3. aluminum + hydrochloric
More informationChemical Reaction Defn: Chemical Reaction: when starting chemical species form different chemicals.
Chemistry 11 Notes on Chemical Reactions Chemical Reaction Defn: Chemical Reaction: when starting chemical species form different chemicals. Evidence to indicate that a chemical reaction has occurred:
More informationStoichiometry Part 1
Stoichiometry Part 1 Formulae of simple compounds Formulae of simple compounds can be deduced from their ions/valencies but there are some that you should know off by heart. You will learn these and more
More informationFunsheet 3.0 [WRITING & BALANCING EQUATIONS] Gu/R. 2017
Funsheet 3.0 [WRITING & BALANCING EQUATIONS] Gu/R. 2017 Balance the following chemical equations. Remember, it is not necessary to write "1" if the coefficient is one. 1. N 2 + H 2 NH 3 2. KClO 3 KCl +
More informationGet Discount Coupons for your Coaching institute and FREE Study Material at
Atoms and Molecules 8th century marked the recognition of difference between compounds and elements and scientists started thinking about combining and reactions of elements. Antoine L Lavoisier laid the
More information(DO NOT WRITE ON THIS TEST)
Final Prep Chap 8&9 (DO NOT WRITE ON THIS TEST) Multiple Choice Identify the choice that best completes the statement or answers the question. 1. After the correct formula for a reactant in an equation
More informationChapter 5 Chemical Calculations
Calculating moles Moles and elements Moles and compounds Moles and gases Moles and solutions Calculating formulae Finding the formula Chapter 5 Chemical Calculations Moles and chemical equations Checklist
More informationStudy Guide: Stoichiometry
Name: Study Guide: Stoichiometry Period: **YOUR ANSWERS MUST INCLUDE THE PROPER NUMBER OF SIG FIGS AND COMPLETE UNITS IN ORDER TO RECEIVE CREDIT FOR THE PROBLEM.** BALANCE THE FOLLOWING EQUATIONS TO USE
More informationUnit Learning Targets (L.T.):
Unit 9: Chemical Equations and Reactions Chapters 8 and 19 Name Block Unit Learning Targets (L.T.): By the end of the unit, students will be able to: Chapter 8: 1. Correctly write and balance chemical
More informationFormulae and Equations
Formulae and Equations 1 of 41 Boardworks Ltd 2016 Formulae and Equations 2 of 41 Boardworks Ltd 2016 Forming different compounds 3 of 41 Boardworks Ltd 2016 Elements are made up of just one type of atom.
More informationChapter 6 Inorganic and Organic Compounds: Names and Formulas
Chapter 6 Inorganic and Organic Compounds: Names and Formulas 6.1 Octet Rule and Ions 1 Octet Rule An octet is 8 valence electrons is associated with the stability of the noble gases does not occur with
More information1) What is the volume of a tank that can hold Kg of methanol whose density is 0.788g/cm 3?
1) Convert the following 1) 125 g to Kg 6) 26.9 dm 3 to cm 3 11) 1.8µL to cm 3 16) 4.8 lb to Kg 21) 23 F to K 2) 21.3 Km to cm 7) 18.2 ml to cm 3 12) 2.45 L to µm 3 17) 1.2 m to inches 22) 180 ºC to K
More informationSCIENCE JSUNIL TUTORIAL CLASS 9. Activity 1
Activity Objective To understand, that there is a change in mass when a chemical change takes place. (To understand law of conservation of mass experimentally). Procedure. Take one of the following sets,
More informationCHAPTER - 3 Atoms and Molecules
CHAPTER - 3 Atoms and Molecules CONCEPT DETAILS KEY CONCEPTS : [ *rating as per the significance of concept] 1. Laws of Chemical Combination *** 2. John Daltons Atomic Theory ** 3. Atoms, ions & Chemical
More informationTOPIC 9. CHEMICAL CALCULATIONS III - stoichiometry.
TOPIC 9. CHEMICAL CALCULATIONS III - stoichiometry. Stoichiometric calculations. By combining a knowledge of balancing equations with the concept of the mole, it is possible to easily calculate the masses
More informationPractice Packet Unit 3: Moles & Stoichiometry
PRACTICE PACKET: Unit 3 Moles & Stoichiometry Regents Chemistry: Mr. Palermo Practice Packet Unit 3: Moles & Stoichiometry Vocabulary: Lesson 1: Lesson 2: Lesson 3: Lesson 4: Lesson 5: Lesson 6: Lesson
More information2H 2 (g) + O 2 (g) 2H 2 O (g)
Mass A AP Chemistry Stoichiometry Review Pages Mass to Mass Stoichiometry Problem (Review) Moles A Moles B Mass B Mass of given Amount of given Amount of unknown Mass of unknown in grams in Moles in moles
More informationUNIT 9 - STOICHIOMETRY
General Stoichiometry Notes STOICHIOMETRY: tells relative amts of reactants & products in a chemical reaction Given an amount of a substance involved in a chemical reaction, we can figure out the amount
More informationCHEMICAL REACTIONS. Types of Reactions. Steps to Writing Reactions
Types of Reactions CHEMICAL REACTIONS There are five types of chemical reactions we will talk about: 1. Synthesis reactions 2. reactions 3. Single displacement reactions 4. reactions 5. Combustion reactions
More informationIGCSE Double Award Extended Coordinated Science
IGCSE Double Award Extended Coordinated Science Chemistry 4.0 - Chemical Formulae and Equations - the chemical symbols for the first 20 elements - And the charges of the ions they form - And use them to
More informationChapter 7. Chemical Reactions
Chapter 7 Chemical Reactions 1 All chemical reactions have two parts Reactants - the substances you start with Products- the substances you end up with The reactants turn into the products. Reactants Products
More informationChemical Equations and Chemical Reactions
Chemical Equations Chemical Equations and Chemical Reactions Chemical equations are concise representations of chemical reactions. Chemical Equations Symbols Used in Chemical Equations The formulas of
More informationUnit 6: Mole Assignment Packet Period:
Unit 6: Mole Assignment Packet Name: Period: A1: Mole Conversions 1. Identify the representative particle in each of the following: (atom, molecule, formula unit) a. CuSO 4 b. H 2 O c. NaCl d. Zn e. Cu
More informationBalancing CHEMICAL EQUATIONS
Balancing CHEMICAL EQUATIONS CHEMICAL REACTIONS involves a chemical change in the identity of one or more chemical species Ex. Rusting of iron (Fe): chemical rxn btwn water and iron involve the breaking
More informationTHE BRIDGING COURSE TO SIXTH FORM CHEMISTRY AT Myton School
THE BRIDGING COURSE TO SIXTH FORM CHEMISTRY AT Myton School Introduction Before you start the AS Chemistry course in September you should have completed this new bridging course for Chemists. It has been
More informationChemical Bonding. Chemical Bonds. Metals, Ions, or Molecules. All Matter Exists as Atoms,
Chemical Bonding Valence electrons (the outer most electrons) are responsible for the interaction between atoms when forming chemical compounds. Another way to say that is that valence electrons are the
More informationIGCSE (9-1) Edexcel - Chemistry
IGCSE (9-1) Edexcel - Chemistry Principles of Chemistry Chemical Formulae, Equations and Calculations NOTES 1.25: Write word equations and balanced chemical equations (including state symbols): For reactions
More informationBALANCING EQUATIONS NOTES
BALANCING EQUATIONS NOTES WHY DO WE NEED TO BALANCE CHEMICAL EQUATIONS? The LAW OF CONSERVATION OF MASS says that matter cannot be created or destroyed. In other words, you cannot end up with any more
More informationHow many hydrogen atoms are there in the empirical formula of propene, C 3 H 6? How many neutrons are there in one atom of 24 Mg?
1 A 2 B 3 C The atomic number of Na is 11. How many electrons are there in a sodium ion, Na +? How many hydrogen atoms are there in the empirical formula of propene, C 3 H 6? What is the mass in grams
More informationHe 1s 2 2 Ne 1s 2 2s 2 2p 6 8 = Ar 1s 2 2s 2 2p 6 3s 2 3p 6 8 = O 1s 2 2s 2 2p 4 6 = S 1s 2 2s 2 2p 6 3s 2 3p 4 6 = 2 + 4
Bonding is the joining of two atoms in a stable arrangement. CHAPTER 7: IONIC COMPOUNDS There are two different kinds of bonding: 1. Ionic bonds result from the transfer of electrons from one element to
More informationChapter 3 - Molecules, Compounds and Chemical Equations
Chapter 3 - Molecules, Compounds and Chemical Equations Section 3.2 two general types of bonding between atoms found in compounds, ionic and covalent ionic bonds result when electrons have been transferred
More informationChapter 7 Prep-Test ID: A. Multiple Choice Identify the letter of the choice that best completes the statement or answers the question.
ID: A Chapter 7 Prep-Test Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. A chemical reaction has NOT occurred if the products have a. the
More informationBell Work 6-Nov How many valence electrons does magnesium and oxygen have? Draw their Lewis dot structures.
Bell Work 6-Nov-2012 How many valence electrons does magnesium and oxygen have? Draw their Lewis dot structures. Objective: You will UNDERSTAND how to write a basic chemical formula Ions Some compounds
More informationA-LEVEL TRANSITION COURSE SUMMER 2018 PART 2: USING CHEMICAL EQUATIONS
A-LEVEL TRANSITION COURSE SUMMER 2018 PART 2: USING CHEMICAL EQUATIONS MASS AQUEOUS VOLUME ` MOLAR MASS GASEOUS VOLUME MOLES CONCENTRATION REVISION FROM LESSON 1 How many moles? 1) Jahin weighs a sample
More informationRegents Chemistry Unit 3- Bonding, Moles & Stoichiometry Study Guide & Pre-Test KEY
Name: Regents Chemistry Unit 3- Bonding, Moles & Stoichiometry Study Guide & Pre-Test KEY Focus Questions for the Unit: How are compounds different... from elements?... from mixtures? What role do valence
More informationReaction Types and Chemical Equations
Cool Chemistry Show Section 4 Reaction Types and Chemical Equations What Do You See? Learning Outcomes In this section you will Represent chemical changes using word equations and chemical equations. Distinguish
More informationFinal Exam Review Questions You will be given a Periodic Table, Activity Series, and a Common Ions Chart CP CHEMISTRY
Final Exam Review Questions You will be given a Periodic Table, Activity Series, and a Common Ions Chart CP CHEMISTRY Part A True-False State whether each statement is true or false. If false, correct
More informationChem!stry. Question 1: Which other chemical elements are diatomic? Write their names and formulae below:
Chem!stry Name: ( ) Class: Date: / / Chemical Symbols and Formulae Chemists use symbols and formulae as a concise way of describing chemical elements and compounds. The symbols of some chemical elements
More informationWorksheet 1: REPRESENTATIVE PARTICLES
Worksheet 1: REPRESENTATIVE PARTICLES Directions: For each substance below, state the representative particle. If the RP is a molecule, state the number of atoms that make up the molecule. If the RP is
More informationTest Review # 6. Chemistry R: Form TR6-10A
Chemistry R: Form TR6-10A TEST 6 REVIEW Name Date Period Test Review # 6 The Stock System.The stock system is a set of rules for naming compounds of metals and non metals. The metal always comes first
More informationSemester 1 Review Chemistry
Name Period Date Semester 1 Review Chemistry Units & Unit Conversions Ch. 3 (p. 73-94) PART A SI UNITS What type of measurement is indicated by each of the following units? Choices are in the last column.
More informationSolutions to the Extra Problems for Chapter 8
Solutions to the Extra Problems for Chapter 8. The answer is 83.4%. To figure out percent yield, you first have to determine what stoichiometry says should be made: Mass of MgCl 4.3 amu + 35.45 amu 95.
More informationStoichiometry. Introduction. Rx between Hydrogen and Oxygen can be described as: Balanced equation: Or Avogadros Number: (number of Molecules)
Stoichiometry Introduction Rx between Hydrogen and Oxygen can be described as: Balanced equation: Or Or Avogadros Number: (number of Molecules) Or Moles (amount of a substance containing avogadros number
More informationNaming Ionic Compounds with Two Elements
Chapter 6 Lecture Chapter 6 Ionic and Molecular Compounds 6.3 Naming and Writing Ionic Compounds Fifth Edition Naming of Ionic Compounds In the name of an ionic compound, the positive ion (first ion) is
More informationChemistry: Final Exam Review. June, 2017 Mrs. Barbarito, Mrs. Corcoran, Ms. Guglielmo
Chemistry: Final Exam Review June, 2017 Mrs. Barbarito, Mrs. Corcoran, Ms. Guglielmo 1 CHEMISTRY FINAL EXAM FORMAT TIME: 1.5 HOURS 1. MULTIPLE CHOICE 2. BRIEF ANSWERS AND PROBLEMS 3. CONTENT READING WITH
More informationCHEMICAL REACTION. Engr. Yvonne Ligaya F. Musico 1
CHEMICAL REACTION Engr. Yvonne Ligaya F. Musico 1 Chemical Reaction Engr. Yvonne Ligaya F. Musico 2 Introduction Chemical reactions occur when bonds between the outermost parts of atoms are formed or broken
More informationChem A Ch. 9 Practice Test
Name: Class: Date: Chem A Ch. 9 Practice Test Matching Match each item with the correct statement below. a. product d. balanced equation b. reactant e. skeleton equation c. chemical equation 1. a new substance
More information2. Indicators of Chemical Rxns. Abbreviations of State (g) gas (l) liquid (s) solid (aq) aqueous a substance dissolved in water
Unit 6 Chemical Reactions 1. Parts of a Chemical Reaction 2. Indicators of a Chemical Reaction 3. Enthalpy 4. Balancing Chemical Equations 5. Word Equations 6. Classifying Chemical Reactions 7. Predicting
More informationName... Requirements for the task and Chemistry lessons
Name... HAUTLIEU SCHOOL CHEMISTRY Pre AS and IB Diploma Task Expectations All sections of the task will be attempted please check you have answered all questions (even those on the back page) Answers should
More information1.24 Calculations and Chemical Reactions
1.24 Calculations and Chemical Reactions Converting quantities between different substances using a balanced equation A balanced chemical equation tells us the number of particles of a substance which
More informationUnit 4: Reactions and Stoichiometry
Unit 4: Reactions and Stoichiometry Reactions Chemical equation Expression representing a chemical reaction Formulas of reactants on the left side Formulas of products on the right side Arrow(s) connect(s)
More informationCHEMICAL REACTIONS. Introduction. Chemical Equations
CHEMICAL REACTIONS Chemistry I Chapter 7 1 Chemical Equations Their Job: Depict the kind of reactants and products and their relative amounts in a reaction. 4 Al (s) + 3 O 2 (g) ---> 2 Al 2 O 3 (s) The
More informationChapter 8. Chemical Equations. Flames and sparks result when aluminum foil is dropped Into liquid bromine.
Chapter 8 Chemical Equations Flames and sparks result when aluminum foil is dropped Into liquid bromine. Introduction to General, Organic, and Biochemistry 10e John Wiley & Sons, Inc Morris Hein, Scott
More informationChapter 8 Chemical Reactions
Chemistry/ PEP Name: Date: Chapter 8 Chemical Reactions Chapter 8: 1 7, 9 18, 20, 21, 24 26, 29 31, 46, 55, 69 Practice Problems 1. Write a skeleton equation for each chemical reaction. Include the appropriate
More informationNomenclature (Naming Compounds) and Chemical Formulas
Nomenclature (Naming Compounds) and Chemical Formulas 1 Ions formed from a single atom Monatomic Ions Charges are determined by whether ion has lost electrons (+) or gained electrons (-) Symbols are written
More informationTHE BRIDGING COURSE TO SIXTH FORM CHEMISTRY Birchwood High School
THE BRIDGING COURSE TO SIXTH FORM CHEMISTRY Birchwood High School Mrs Ryan Chemistry Please also access the website below which is a link to a really good PPT that will help to bridge the gap between GCSE
More informationName Honors Chemistry / / Chemical Equations Reactions
Name Honors Chemistry / / Chemical Equations Reactions Like everything else in chemistry, chemical equations follow a few basic patterns. Today we will begin to look at the first of these patterns and
More informationNCEA Chemistry 2.2 Identify Ions AS 91162
NCEA Chemistry 2.2 Identify Ions AS 91162 What is this NCEA Achievement Standard? When a student achieves a standard, they gain a number of credits. Students must achieve a certain number of credits to
More informationUnit 9 Stoichiometry Notes
Unit 9 Stoichiometry Notes Stoichiometry is a big word for a process that chemist s use to calculate amounts in reactions. It makes use of the coefficient ratio set up by balanced reaction equations to
More informationChapter 2. The Components of Matter
Chapter 2. The Components of Matter 1 The Periodic Table (Section 2.6) 13 Al 26.981 Main Idea: 1. Groups: Old numbering system: New IUPAC numbering system: 2. Periods: 3. Know the names and properties
More information