1. (i) Give an equation for the dissociation of propanoic acid and hence an expression for its dissociation constant, K a. ...
|
|
- Felix Carter
- 5 years ago
- Views:
Transcription
1 1. (i) Give an equation for the dissociation of propanoic acid and hence an expression for its dissociation constant, K a.... At 5 C K a for propanoic acid is mol dm 3. Find the ph of a solution of propanoic acid of concentration mol dm 3. State any assumptions you make. (iii) Increasing the temperature of the propanoic acid solution causes the ph to decrease. What does this tell you about the enthalpy of dissociation? Justify your answer Using the following data, construct a Born-Haber cycle for potassium chloride and use it to find the electron affinity of chlorine. H/kJ mol 1 First ionisation energy of potassium +419 Enthalpy of atomisation of potassium +89. Enthalpy of atomisation of chlorine Enthalpy of formation of potassium chloride Lattice enthalpy of potassium chloride 711 (9) (6) NT Exampro 1
2 3. (a) What name is given to the enthalpy change of the following reaction? K + (g) + Br (g) KBr(s)... (b) Use the following data to construct a fully-labelled energy diagram and use it to calculate the enthalpy change in (a). H / kj mol 1 Br Br(g) +4 Br(g) + e Br 348 K(s) + ½Br KBr(s) 39 K(s) K(g) +90 K(g) K + (g) + e +44 (6) (Total 7 marks) NT Exampro
3 4. A Born-Haber cycle for the formation of calcium oxide is shown below. + Ca (g) + O (g) + Ca (g) + O(g) + e H 5 + Ca (g) + ½ O (g) + e + Ca (g) + ½ O (g) + e Ca(g) + ½ O (g) Ca(s) + ½ O (g) CaO(s) Data H/kJ mol 1 : H 1 = +193; H = 590; H 3 = +1150; H 4 = +48; H 6 = 3513; H 1 = 635. (i) Identify the change which represents the lattice enthalpy of CaO Use the data above to calculate H 5. H H H H H H 6 NT Exampro 3
4 (iii) Use this value of H 5 to calculate the first electron affinity of oxygen, given that the second electron affinity of oxygen is +844 kj mol 1. (Total 6 marks) 5. Benzene reacts with concentrated nitric acid in the presence of concentrated sulphuric acid at about 50 ºC in an electrophilic substitution reaction to give nitrobenzene. (a) (i) Give the equation representing the overall reaction. (b) (iii) Give the equation representing the formation of the electrophile. Give the mechanism for the reaction of the electrophile with benzene. In an experiment to determine the kinetics of this reaction, it is found that the attack of the electrophile on the benzene ring is the rate determining step. The following data shows the effect of changing the concentrations on the rate: (i) [benzene] (relative) [electrophile] (relative) Rate (relative) What is the order with respect to benzene.. the electrophile? Write a rate equation for the reaction. (iii) In some electrophilic substitution reactions of aromatic compounds, the rate determining step is the production of the electrophile. In such cases what would be the order of the reaction with respect to the aromatic compound? (c) The equation representing the hydrogenation of ethene is NT Exampro 4
5 H C CH +H H 3 C CH 3 H = 10 kj mol 1 (i) Assuming that benzene consists of a ring with three double bonds, predict the enthalpy change for the reaction + 3H (iii) The enthalpy of hydrogenation of benzene is actually 05 kj mol 1. What can you deduce from this and your answer to part (i) about the stability of the benzene ring? Use an enthalpy level diagram to illustrate your answer. The compound cyclo octatetraene has an enthalpy of hydrogenation of 480 kj mol 1; the molecule, unlike that of benzene, is not flat. Suggest in terms of the possibility of orbital overlap why cyclo octatetraene does not show the same type of stability as benzene, despite superficial similarities in their structures. (Total 14 marks) 6. (a) Define the term lattice enthalpy NT Exampro 5
6 (b) Using the following data, construct a Born-Haber cycle for sodium fluoride and from it determine the lattice enthalpy of sodium fluoride. Process The value of the energy change/kj mol 1 (c) Na(g) Na+(g) + e +494 F (g) F(g) +158 F(g) + e F (g) 348 Na(s) + ½F (g) NaF(s) 569 Na(s) Na(g) +109 The table below gives some information about the hydroxides of the Group elements. (i) salt magnesium hydroxide calcium hydroxide strontium hydroxide barium hydroxide lattice enthalpy/kj mol l hydration enthalpy/kj mol l solubility in water/g per 100 g of water Explain why energy is required to break up an ionic lattice. Suggest why the lattice enthalpies of the hydroxides of Group metals become more exothermic from Ba(OH) to Mg(OH). (5) NT Exampro 6
7 (iii) Suggest why the lattice enthalpy of beryllium hydroxide, Be(OH), cannot be predicted from the data in the table. (iv) Explain why energy is released when ions are hydrated. (v) Hence, account for the trend in solubilities from Ba(OH) to Mg(OH) (Total 16 marks) 7. (a) (i) Draw a Born-Haber cycle for the formation of magnesium chloride, MgCl. Use the values below to calculate the lattice enthalpy of magnesium chloride. H 1st electron affinity of chlorine 364 1st ionisation energy of magnesium +736 /kj mol 1 nd ionisation energy of magnesium Enthalpy of atomisation of chlorine +11 Enthalpy of atomisation of magnesium +150 Enthalpy of formation of MgCl (s) 64 NT Exampro 7
8 (b) (i) The value of the lattice enthalpy of magnesium chloride calculated from a purely ionic model is 36 kj mol 1. Explain why this differs from the value determined from a Born-Haber cycle. Use the following data to answer the questions in this section. H /kj mol 1 H hydration of Sr H hydration of Ba H hydration of OH 460 Lattice enthalpy of Sr(OH) 1894 Lattice enthalpy of Ba(OH) 1768 Explain why the lattice enthalpy of strontium hydroxide is different from that of barium hydroxide. Explain why the hydration enthalpy of a cation is exothermic. (5) NT Exampro 8
9 (iii) Use the lattice enthalpy and hydration enthalpy values to explain why barium hydroxide is more soluble in water than strontium hydroxide. 8. (a) The Born-Haber cycle for the formation of sodium chloride is shown below. Na + (g) Na (g) + Cl(g) + e Cl (g) + e Na(g) + Cl (g) Na(s) Cl (g) + Na (g) + Cl (g) + Na Cl (s) (4) (Total 15 marks) NT Exampro 9
10 Use the data below to calculate the lattice enthalpy of sodium chloride. Enthalpy change Value of the enthalpy change /kj mol 1 Enthalpy of atomisation of sodium st ionisation energy of sodium +494 Enthalpy of formation of sodium chloride 411 Enthalpy of atomisation of chlorine +11 Electron affinity of chlorine 364 (b) (c) Sodium chloride and magnesium oxide have very similar crystal lattices. Suggest why the lattice enthalpy of magnesium oxide is very much larger than that of sodium chloride The lattice enthalpy of silver iodide can be calculated but the experimental value does not match the calculated value as well as those for sodium chloride match each other. Explain why the calculated and experimental values for silver iodide are different (Total 6 marks) NT Exampro 10
11 9. You are required to carry out a quantitative exercise to find the enthalpy change when a Group 1 compound, S, dissolves in water. (13 marks] Quantitative exercise to find the enthalpy change when a Group 1 compound dissolves in water You are provided with: a sample of a Group 1 compound, S, in a specimen tube. You are required to find the molar enthalpy change when S dissolves in water. - PROCEDURE S(s) + aq S(aq) Rinse out a 50 cm3 measuring cylinder with distilled water then use the measuring cylinder to measure 50 cm3 of distilled water into a dry plastic cup held firmly in a beaker. Place the thermometer in the distilled water in the cup. Weigh the specimen tube containing S. Record the mass of the tube and S in the first table below. Measure the temperature of the distilled water in the cup to the nearest 0. C. Record the temperature in the second table below. (4) Empty the sample of S from the specimen tube into the plastic cup, stirring gently with the thermometer. (The accuracy of your results will not be affected if a small amount of S is left in the tube.) Continue stirring until all of the solid has dissolved then record the steady temperature of the solution to the nearest 0. C. Record the temperature in the second table below. (5) Weigh the emptied specimen tube and record the mass in the first table below. Mass of specimen tube + S Mass of emptied specimen tube Mass of S used Temperature of distilled water before adding S T 1 C Steady temperature of solution, T C Calculate the change in temperature, T, by subtracting T 1 from T. g g g T = T -T 1 = =... C (6) NT Exampro 11
12 Calculations and questions (a) Calculate the molar enthalpy change when S dissolves in water using the formula 17.8 T H = kj mol 1 Mass of S used Include a sign and units with your value of H which should be expressed to an appropriate number of significant figures. (b) H = Suggest a change to the procedure, using the same apparatus, that may lead to a more accurate value of the molar enthalpy change. Explain the reason for your suggestion (a) Using the following data, construct a Born-Haber cycle for potassium chloride and use it to calculate the electron affinity of chlorine. H / kj mol 1 1st ionisation energy of potassium Enthalpy of atomisation of potassium Enthalpy of atomisation of chlorine Enthalpy of formation of KCl(s) Lattice enthalpy of potassium chloride 711 (Total 13 marks) NT Exampro 1
13 (b) (c) Calcium is in the same period in the periodic table as potassium. The lattice enthalpy of calcium chloride is 58 kj mol 1. Explain why this is so different from the value for potassium chloride given in (a). Lattice enthalpies may be calculated based on an assumption about the structure of the solid or found experimentally using data in the Born-Haber cycle. The experimental lattice enthalpy of potassium chloride is 9 kj mol 1 more exothermic than that calculated; for calcium chloride the experimental value is 35 kj mol 1 more exothermic than that calculated. Suggest why the calculated and experimental values are different in both compounds. (5) NT Exampro 13
14 (d) The solubility of calcium sulphate in water at room temperature is much greater than that of barium sulphate. Suggest reasons for this difference. (Total 1 marks) 11. The formation of magnesium chloride from magnesium and chlorine may be represented by the following Born-Haber cycle: (a) Mg + (g) + Cl (g) + e Mg(g) + Cl (g) Mg(s) + Cl (g) Define the terms: Lattice enthalpy. Mg + (g) + Cl(g) + e Mg + (g) + Cl (g) MgCl (s) NT Exampro 14
15 Enthalpy of atomisation (b) (i) Identify on the diagram the chance representing the enthalpy of atomisation of magnesium. Use the data below to calculate the first electron affinity of chlorine. Enthalpy change Enthalpy of atomisation of magnesium 1st Ionisation energy of magnesium nd Ionisation energy of magnesium Enthalpy of formation of magnesium chloride Enthalpy of atomisation of chlorine Lattice enthalpy of magnesium chloride Value of the enthalpy change / kj mol NT Exampro 15
16 (c) Hydrogen gas reacts with sodium metal to form an ionic solid, NaH, which contains sodium cations. Draw a Born-Haber cycle which could be used to determine the electron affinity of hydrogen. 1. (a) Write an equation which represents the change when the second electron affinity of oxygen is measured.... (Total 11 marks) NT Exampro 16
17 (b) Construct a Born-Haber cycle and use it and the data below to calculate the second electron affinity of oxygen. H / kj mol 1 Enthalpy of atomisation of magnesium +150 Bond energy of O == O in oxygen st ionisation energy of magnesium +736 nd ionisation energy of magnesium Ist electron affinity of oxygen 14 Lattice enthalpy of magnesium oxide 3889 Enthalpy of formation of magnesium oxide 60 (c) (i) MgO(s) has the same crystal structure as NaCl(s). The lattice enthalpy of NaCl(s) is 771 kj mol 1 whilst that of MgO(s) is 3889 kj mol 1. Explain the difference in lattice enthalpies (4) (4) Despite its high lattice enthalpy sodium chloride is soluble in water. (iii) What other factor is important in enabling compounds such as sodium chloride to be soluble in polar solvents such as water?... Explain why magnesium oxide is insoluble in water. NT Exampro 17
18 (Total 13 marks) 13. (a) The bombardier beetle Metrius contractus persuades potential predators to disappear by firing a boiling mixture of irritants at them. The reaction producing this ammunition is a redox reaction, H O being the oxidising agent. (b) The two half-reactions involved are: (i) (iii) OH OH H O + H + e O O H O + E /V + + H + e Write the overall equation for the reaction and show that the reaction is feasible. The beetle makes use of an enzyme catalyst in the reaction. Explain in general terms how catalysts increase the rate of a chemical reaction using a graph of the Maxwell-Boltzmann distribution of molecular energies. The reaction is highly exothermic; in principle its enthalpy of reaction could be found by using average bond enthalpies. By a consideration of the structure and bonding in the compounds involved, suggest why the use of the average bond enthalpies for C==O, C C, C==C and O H would give a highly inaccurate answer for the enthalpy of reaction. On heating hydrogen peroxide decomposes according to the equation H O H O + O Hydrogen peroxide is marketed as an aqueous solution of a given volume strength. The common 0-volume solution gives 0 dm3 of oxygen from 1 dm3 of solution. What is the concentration in g dm 3 of such a solution? (Molar volume of any gas at the temperature and pressure of the experiment is 4 dm3.) (5) NT Exampro 18
19 (c) Hydrogen peroxide, H O, can also act as a reducing agent. The rapid oxidation of hydrogen peroxide was used in World War II to generate steam to launch the V1 flying bomb. H O (100 volume) was reacted with acidified potassium manganate(vii) solution. (i) Write the half-equation for the oxidation of hydrogen peroxide to oxygen, O. (iii) The MnO 4 ions are reduced to Mn+ during the reaction. Derive the overall equation for the reaction between H O and acidified KMnO 4. Suggest in terms of the collision theory of chemical kinetics why 100-volume hydrogen peroxide (this gives l00 dm3 of oxygen from 1 dm3 of hydrogen peroxide when it decomposes to water and oxygen) was used rather than the more common 0-volume solution. (Total 18 marks) 14. (a) Define the term lattice enthalpy. (b) (i) Construct a Born-Haber cycle for the formation of calcium chloride, CaCl. Use the cycle and the data below to calculate the lattice enthalpy of calcium chloride. H / kj mol 1 Enthalpy of atomisation of calcium st ionisation energy of calcium +590 nd ionisation energy of calcium Enthalpy of formation of calcium chloride 795 Enthalpy of atomisation of chlorine +11 Electron affinity of chlorine 370 NT Exampro 19
20 Cycle: (c) (d) Calculation: Explain why the lattice enthalpy of magnesium fluoride, MgF, is more exothermic than that of calcium chloride. The theoretical and actual values of the lattice enthalpy of magnesium fluoride are very similar because magnesium fluoride is almost completely ionic. Explain why magnesium fluoride is almost completely ionic. (5) (Total 13 marks) NT Exampro 0
21 15. (a) Define the terms (i) lattice energy; (b) enthalpy of hydration. Lattice energy and enthalpies of hydration can sometimes be used to rationalise the solubility trend in a series of related salts. (i) Draw a labelled Hess s Law cycle that would enable the enthalpy of solution, H sol, of an ionic solid M+X to be calculated from the lattice energy and enthalpies of hydration of the ions. Express the enthalpy of solution H sol in terms of the other quantities. NT Exampro 1
22 (iii) The approximate relative solubility (relative to magnesium sulphate) of the sulphates of the elements of group are given below. Salt Relative solubility MgSO 4 1 CaSO 4 10 SrSO BaSO 4 l0 6 Explain the reasons for this trend in solubility in terms of changes of lattice energies and enthalpies of hydration. 16. (a) Consider the following equilibrium, which illustrates one industrial method used to produce hydrogen: CH 4 (g) + H O(g) CO (g) + 4H (g) (4) (Total 13 marks) In a certain experiment, 10 g of methane, CH 4, and 54 g of water, H O, were heated in a container of volume 4 dm3. At equilibrium,.0 moles of hydrogen, H, had formed. Write an expression for the equilibrium constant, K c, for the system, and use the data to calculate a value for K c, with units. (b) The following table shows some data for enthalpies of formation, H f. Substance H f /kj mol 1 CH 4 (g) 76 H O(g) 4 CO (g) 394 (8) Use these data to calculate the enthalpy change for the reaction in (a). NT Exampro
23 (c) In practice, the industrial production of hydrogen by this method is conducted at the moderately high pressure of 30 atm, and the high temperature of 750 C, in the presence of a nickel catalyst. Suggest why these conditions are used, considering the factors of rate and yield. (7) (Total 18 marks) NT Exampro 3
The chemical potential energy of a substance is known as its ENTHALPY and has the symbol H.
Enthalpy Changes The chemical potential energy of a substance is known as its ENTHALPY and has the symbol H. During chemical reactions, the enthalpy can increase or decrease. The change in enthalpy during
More information(03) WMP/Jun10/CHEM4
Thermodynamics 3 Section A Answer all questions in the spaces provided. 1 A reaction mechanism is a series of steps by which an overall reaction may proceed. The reactions occurring in these steps may
More information[2] The table below shows the enthalpy changes that are needed to determine the enthalpy change of hydration of magnesium ions.
1 Born Haber cycles provide a model that chemists use to determine unknown enthalpy changes from known enthalpy changes. In this question, you will use a Born Haber cycle to determine an enthalpy change
More informationPage 2. Define the term electron affinity for chlorine (2)
Q1.(a) Define the term electron affinity for chlorine. (b) Complete this Born Haber cycle for magnesium chloride by giving the missing species on the dotted lines. Include state symbols where appropriate.
More information13 Energetics II. Eg. Na (g) Na + (g) + e - ΔH = +550 kj mol -1
13 Energetics II First ionisation energy I(1) or IE (1): the energy required to remove one mole of electrons from one mole of the gaseous atoms of an element to 1 mole of gaseous monopositive ions. Eg.
More information5.2 Energy. N Goalby chemrevise.org Lattice Enthalpy. Definitions of enthalpy changes
5.2 Energy 5.2.1 Lattice Enthalpy Definitions of enthalpy changes Enthalpy change of formation The standard enthalpy change of formation of a compound is the energy transferred when 1 mole of the compound
More information12A Entropy. Entropy change ( S) N Goalby chemrevise.org 1. System and Surroundings
12A Entropy Entropy change ( S) A SPONTANEOUS PROCESS (e.g. diffusion) will proceed on its own without any external influence. A problem with H A reaction that is exothermic will result in products that
More informationAQA A2 CHEMISTRY TOPIC 5.1 THERMODYNAMICS BOOKLET OF PAST EXAMINATION QUESTIONS
AQA A2 CHEMISTRY TOPIC 5.1 THERMODYNAMICS BOOKLET OF PAST EXAMINATION QUESTIONS 1 1. A Born Haber cycle for the formation of calcium sulphide is shown below. The cycle includes enthalpy changes for all
More information1.8 Thermodynamics. N Goalby chemrevise.org. Definitions of enthalpy changes
1.8 Thermodynamics Definitions of enthalpy changes Enthalpy change of formation The standard enthalpy change of formation of a compound is the energy transferred when 1 mole of the compound is formed from
More informationShow by calculation that the starting concentration of the manganate(vii) ions was mol dm 3.
1. Manganate(VII) ions react with ethanedioate ions in acidic solution. MnO 4 (aq) + 16H + (aq) + 5C O 4 (aq) Mn + (aq) + 8H O(l) + 10CO (g) (a) In a particular experiment 00 cm of aqueous potassium manganate(vii),
More information1.8 Thermodynamics. Lattice formation enthalpy Enthalpy change when 1 mole of a solid ionic compound is formed from its gaseous ions
1.8 Thermodynamics Review: In 1.3 we looked at ionic bonding and learned that: Giant ionic lattice structure Ionic bonding: Strong electrostatic force of attraction between oppositely charged ions that
More information1. (a) Give the full electronic configuration of an atom of oxygen and give the reason why oxygen is classed as a p-block element
1. (a) Give the full electronic configuration of an atom of oxygen and give the reason why oxygen is classed as a p-block element. (c) (d) Write equations to show the changes occurring when the first and
More informationFor the element X in the ionic compound MX, explain the meaning of the term oxidation state.
1. (a) By referring to electrons, explain the meaning of the term oxidising agent.... For the element X in the ionic compound MX, explain the meaning of the term oxidation state.... (c) Complete the table
More informationA-level CHEMISTRY 7405/1. Paper 1: Inorganic and Physical Chemistry. SPECIMEN MATERIAL v1.2
SPECIMEN MATERIAL v1.2 Please write clearly in block capitals. Centre number Candidate number Surname Forename(s) Candidate signature A-level CHEMISTRY Paper 1: Inorganic and Physical Chemistry Specimen
More informationQ = Enthalpy change for the formation of calcium chloride (P). D Twice the enthalpy change of atomization of chlorine (S).
1 What is the equation for the first electron affinity of sulfur? S(s) + e S (g) S(g) + e S (g) S(s) S + (g) + e S(g) S + (g) + e 2 The diagram shows a orn-haber cycle for calcium chloride. It is not drawn
More informationZAHID IQBAL WARRAICH
Q1 (a) (i) What is meant by the term lattice energy? (ii) Write an equation to represent the lattice energy of MgO. (b) The apparatus shown in the diagram can be used to measure the enthalpy change of
More informationQ1. (a) Explain the meaning of the terms mean bond enthalpy and standard enthalpy of formation. Mean bond enthalpy
Q1. (a) Explain the meaning of the terms mean bond enthalpy and standard enthalpy of formation. Mean bond enthalpy......... Standard enthalpy of formation............ (5) (b) Some mean bond enthalpies
More information10. Group 2. N Goalby chemrevise.org. Group 2 reactions. Reactions with oxygen. Reactions with water.
10. Group 2 Atomic radius Atomic radius increases down the Group. As one goes down the group, the atoms have more shells of electrons making the atom bigger. Melting points Down the group the melting points
More informationThermodynamics. Standard enthalpy change, H
Standard enthalpy change, H Thermodynamics Enthalpy change, H, is defined as the heat energy change measured under conditions of constant pressure. The value of the enthalpy change for a particular reaction
More informationSummary Term 2 Chemistry STPM Prepared by Crystal Goh AI Tuition Centre
Summary Term Chemistry STPM Prepared by Crystal Goh AI Tuition Centre 017713136 Period 3 elements property Na Mg Al Si P (P 4 ) Type of element Metal Metalloid Non-metal Structure Giant metallic lattice
More informationIB Topics 5 & 15 Multiple Choice Practice
IB Topics 5 & 15 Multiple Choice Practice 1. Which statement is correct for this reaction? Fe 2O 3 (s) + 3CO (g) 2Fe (s) + 3CO 2 (g) ΔH = 26.6 kj 13.3 kj are released for every mole of Fe produced. 26.6
More information5.2.1 Answers Lattice Enthalpy 2012
5.2.1 Answers Lattice Enthalpy 2012 Introduction In this topic we will construct a Born-Haber cycle (or lattice enthalpy cycle) which allows us to calculate numerical values for processes which occur in
More information3.2.6 Group II. Trends in Chemical properties. 164 minutes. 161 marks. Page 1 of 19
3.2.6 Group II Trends in Chemical properties 164 minutes 161 marks Page 1 of 19 Q1. (a) A small sample of barium metal was added to water in a flask. When the reaction had ceased, the contents of the flask
More informationMay 09, Ksp.notebook. Ksp = [Li + ] [F + ] Find the Ksp for the above reaction.
example: Constant Product K sp Solubility Product Constant Some compounds dissolve in water Some compounds dissolve better than others The more that a compound can dissolve, the more soluble the compound
More information, is formed when iron metal reacts with. iodine. The table below shows enthalpy changes involving iron, iodine and iron(ii) iodide.
1 Iron(II) iodide, FeI 2, is formed when iron metal reacts with (a) iodine. The table below shows enthalpy changes involving iron, iodine and iron(ii) iodide. Enthalpy change / kj mol 1 Formation of iron(ii)
More informationCHEMISTRY 2815/01. Trends and Patterns. OXFORD CAMBRIDGE AND RSA EXAMINATIONS Advanced GCE
OXFORD CAMBRIDGE AND RSA EXAMINATIONS Advanced GCE CHEMISTRY 2815/01 Trends and Patterns Tuesday 25 JANUARY 2005 Afternoon 1 hour Candidates answer on the question paper. Additional materials: Data Sheet
More informationCHERRY HILL TUITION AQA CHEMISTRY A2 PAPER Section A (2 marks) (1 mark) (Extra space) Property
2 Section A Answer all questions in the spaces provided. 1 (a) Define the term lattice enthalpy of dissociation. 1 (b) Lattice enthalpy can be calculated theoretically using a perfect ionic model. Explain
More informationExplain why the bond enthalpy of a Cl Cl bond is greater than that of a Br Br bond
Q1. The table below gives some values of standard enthalpy changes. Use these values to answer the questions. Name of enthalpy change H ο /kj mol 1 Enthalpy of atomisation of chlorine +121 Electron affinity
More informationCHERRY HILL TUITION AQA CHEMISTRY A2 PAPER Section A. Answer all questions in the spaces provided.
2 Section A Answer all questions in the spaces provided. 1 This question is about bond dissociation enthalpies and their use in the calculation of enthalpy changes. 1 (a) Define bond dissociation enthalpy
More information15.2 Born-Haber Cycle
15.2 Born-Haber Cycle Our calculations of enthalpies so far have involved covalent substances. Now we need to look at the enthalpy changes involved in the formation of giant ionic lattices. Lattice enthalpy
More informationA Level Chemistry. Ribston Hall High School. Pre Course Holiday Task. Name: School: ii) Maths:
A Level Chemistry Ribston Hall High School Pre Course Holiday Task Name: School: GCSE Grades in i) Chemistry or Science: ii) Maths: 1 The following are a series of questions on topics you have covered
More informationQuestions Booklet. UNIT 1: Principles & Applications of Science I CHEMISTRY SECTION. Level 3 Applied Science. Name:.. Teacher:..
Level 3 Applied Science UNIT 1: Principles & Applications of Science I CHEMISTRY SECTION Questions Booklet Name:.. Teacher:.. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 1 1. State the relative
More information2 Answer all the questions. CO, in the presence of aqueous hydrochloric acid, HCl(aq).
2 Answer all the questions. 1 A student investigates the reaction between iodine, I 2, and propanone, (CH 3 ) 2 CO, in the presence of aqueous hydrochloric acid, HCl(aq). The results of the investigation
More informationQUESTIONSHEETS ENERGETICS II ENTHALPY OF ATOMISATION ENTROPY AND FREE ENERGY CHANGE PRINCIPLES OF ELECTROCHEMICAL CELLS
CHEMISTRY QUESTIONSHEETS A2 Level A2 TOPIC 17 ENERGETICS II Questionsheet 1 Questionsheet 2 Questionsheet 3 Questionsheet 4 Questionsheet 5 Questionsheet 6 Questionsheet 7 Questionsheet 8 Questionsheet
More informationExam Style Questions
Calderglen High School Chemistry Department CfE Higher Chemistry Unit 1: Chemical Changes and Structure Exam Style Questions Page 2 1.1 Periodicity (25 marks) Page 6 1.2 Bonding and Structure part 1 (25
More information(a) (i) Give the equation representing the overall reaction. (1) Give the equation representing the formation of the electrophile.
1. Benzene reacts with concentrated nitric acid in the presence of concentrated sulphuric acid at about 50 º in an electrophilic substitution reaction to give nitrobenzene. (a) Give the equation representing
More informationlattice formation from gaseous ions
BORN HABER CYCLES The Born Haber cycles is an adaption of Hess s law to calculate lattice enthalpy from other data The lattice enthalpy cannot be determined directly. We calculate it indirectly by making
More information26 s-block chemistry
26 s-block chemistry Answers to worked examples WE 26.1 Estimating the enthalpy change of formation of lithium nitride (Li 3 N) (on p. 1178 in Chemistry 3 ) Estimate a value for the enthalpy change of
More informationKOH(aq) + HNO 3 (aq) KNO 3 (aq) + H 2 O(l) A 52 B 26 C +26 D +52. (Total for Question = 1 mark) 2 Calculate the enthalpy change, in kj mol _ 1
1 When 0.1 mol of aqueous potassium hydroxide was added to 0.1 mol of nitric acid, 5200 J were transferred to the surroundings. What is the enthalpy change, in kj mol 1, for this reaction? 52 26 C +26
More informationCHEM5. (JAN12CHEM501) WMP/Jan12/CHEM5. General Certificate of Education Advanced Level Examination January 2012
Centre Number Surname Candidate Number For Examiner s Use Other Names Candidate Signature Examiner s Initials General Certificate of Education Advanced Level Examination January 2012 Question 1 2 Mark
More informationF321: Atoms, Bonds and Groups Structure & Bonding
F321: Atoms, Bonds and Groups Structure & Bonding 1. This question is about different models of bonding and molecular shapes. Magnesium sulfide shows ionic bonding. What is meant by the term ionic bonding?
More informationTOPIC 17 ANSWERS & MARK SCHEMES QUESTIONSHEET 1 ENTHALPY OF ATOMISATION
QUESTIONSHEET 1 ENTHALPY OF ATOMISATION a) The standard enthalpy of atomisation of an element is the energy required (½) to produce 1 mole (½) of gaseous atoms (½) from the element in its standard state
More informationLower Sixth Chemistry. Sample Entrance Examination
Lower Sixth Chemistry Sample Entrance Examination Time allowed: 60 minutes Name: Total : 60 Marks INSTRUCTIONS : Answer all questions Answers should be written in the spaces provided Dictionaries or reference
More information5 Chemical Energetics
5 Chemical Energetics Definition: Enthalpy change is the amount of heat energy taken in or given out during any change in a system provided the pressure is constant. In an exothermic change energy is transferred
More informationNATIONAL 5 CHEMISTRY
Farr High School NATIONAL 5 CHEMISTRY Unit 1 Chemical Changes and Structure Question Booklet 1 Rates of Reaction 1. Explain how the following would affect the rate of the reaction between 1.0 g of magnesium
More informationPractice I: Chemistry IGCSE
Practice I: Chemistry IGCSE cristian.obiol@gmail.com 1) Explain the following processes related to changes of states of matter. -Melting:... -Vaporization:... -Freezing:... -Condensation:... -Sublimation:...
More informationENERGETICS. Energy changes which take place during a chemical reaction can be represented on an energy (enthalpy) profile diagram.
ENERGETICS All types of chemical reaction involve changes in energy. When energy is emitted it can take a number of forms, but the most common form is as heat energy. Heat energy is called enthalpy. Enthalpy
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 informationAdvanced Subsidiary Unit 1: The Core Principles of Chemistry
Write your name here Surname Other names Edexcel GCE Centre Number Chemistry Advanced Subsidiary Unit 1: The Core Principles of Chemistry Candidate Number Tuesday 15 May 2012 Afternoon Time: 1 hour 30
More information2 Answer all the questions. 1 Born Haber cycles can be used to calculate enthalpy changes indirectly.
2 Answer all the questions. 1 Born Haber cycles can be used to calculate enthalpy changes indirectly. (a) The table below shows enthalpy changes for a Born Haber cycle involving potassium sulfide, K 2
More information2 Answer all the questions.
2 Answer all the questions. 1 A sample of the element boron, B, was analysed using a mass spectrometer and was found to contain two isotopes, 10 B and 11 B. (a) (i) Explain the term isotopes. Complete
More informationBeaker A Beaker B Beaker C Beaker D NaCl (aq) AgNO 3(aq) NaCl (aq) + AgNO 3(aq) AgCl (s) + Na 1+ 1
CH 11 T49 MIXING SOLUTIONS 1 You have mastered this topic when you can: 1) define the terms precipitate, spectator ion, suspension, mechanical mixture, solution. 2) write formula equations, complete/total
More informationA-level CHEMISTRY (7405/1)
SPECIMEN MATERIAL A-level CHEMISTRY (7405/1) Paper 1: Inorganic and Physical Chemistry Specimen 2015 Session Time allowed: 2 hours Materials For this paper you must have: the Data Booklet, provided as
More informationIonic Compounds 1 of 31 Boardworks Ltd 2016
Ionic Compounds 1 of 31 Boardworks Ltd 2016 Ionic Compounds 2 of 31 Boardworks Ltd 2016 3 of 31 Boardworks Ltd 2016 Elements and compounds Elements are made up of just one type of atom. Some elements exist
More information1.7 REDOX. Convert these to ionic and half equations and you can see clearly how the electrons are transferred:
1.7 REDOX Oxidation and Reduction: Oxidation and reduction reactions can be identified by looking at the reaction in terms of electron transfer: Our understanding of oxidation and reduction was limited
More information9.1.2 AQUEOUS SOLUTIONS AND CHEMICAL REACTIONS
9.1.2 AQUEOUS SOLUTIONS AND CHEMICAL REACTIONS Work directly from Zumdahl (Chapter 4). Work through exercises as required, then summarise the essentials of the section when complete. To understand the
More informationSIR MICHELANGELO REFALO CENTRE FOR FURTHER STUDIES VICTORIA GOZO
SIR MICHELANGELO REFALO CENTRE FOR FURTHER STUDIES VICTORIA GOZO Page 1 of 7 Half Yearly Exam 2013 Subject: Chemistry 1 st Year Level: Advanced Time: 3 hrs Answer SEVEN (7) questions. All questions carry
More informationAdvanced Subsidiary Unit 1: The Core Principles of Chemistry
Write your name here Surname Other names Pearson Edexcel International Advanced Level Centre Number Chemistry Advanced Subsidiary Unit 1: The Core Principles of Chemistry Candidate Number Friday 26 May
More informationElements in the Periodic Table show a periodic trend in atomic radius. In your answer you should use appropriate technical terms, spelled correctly.
1 The Periodic Table is arranged in periods and groups (a) Elements in the Periodic Table show a periodic trend in atomic radius State and explain the trend in atomic radius from Li to F In your answer
More information2. 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 informationUNIVERSITY OF SIERRA LEONE FOURAH BAY COLLEGE. FIRST EXAMINATION FOR THE DEGREE OF B. Sc. HONOURS LEVEL I SECOND SEMESTER EXAMINATION
UNIVERSITY OF SIERRA LEONE FOURAH BAY COLLEGE CHEM 121 INSTRUCTIONS: FIRST EXAMINATION FOR THE DEGREE OF B. Sc. HONOURS LEVEL I SECOND SEMESTER EXAMINATION WEDNESDAY 12 th SEPTEMBER 2018 13.30 16.45 CHEM
More informationA student adds the following volumes of aqueous sodium thiosulfate, dilute hydrochloric acid and distilled water to the conical flask.
1 When aqueous sodium thiosulfate and dilute hydrochloric acid are mixed, a precipitate of insoluble sulfur is produced. This makes the mixture difficult to see through. Na 2 S 2 O 3 (aq) + 2HCl (aq) S(s)
More information15.2 Born-Haber Cycles
15.2 Born-Haber Cycles 15.2.1 - Define and apply the terms lattice enthalpy and electron affinity Lattice Enthalpy The energy required to completely separate one mole of a solid ionic compound into its
More informationCHEM 122 Unit 1 Introduction to Group Chemistry
DEPARTMENT OF CHEMISTRY FOURAH BAY COLLEGE UNIVERSITY OF SIERRA LEONE CHEM 122 Unit 1 Introduction to Group Chemistry CREDIT HOURS 2.0 MINIMUM REQUIREMENTS C6 in WASSCE Chemistry or equivalent Pass in
More information(A) Composition (B) Decomposition (C) Single replacement (D) Double replacement: Acid-base (E) Combustion
AP Chemistry - Problem Drill 08: Chemical Reactions No. 1 of 10 1. What type is the following reaction: H 2 CO 3 (aq) + Ca(OH) 2 (aq) CaCO 3 (aq) + 2 H 2 O (l)? (A) Composition (B) Decomposition (C) Single
More informationSurname. Number OXFORD CAMBRIDGE AND RSA EXAMINATIONS ADVANCED GCE F325 CHEMISTRY A. Equilibria, Energetics and Elements
Candidate Forename Centre Number Candidate Surname Candidate Number OXFORD CAMBRIDGE AND RSA EXAMINATIONS ADVANCED GCE F325 CHEMISTRY A Equilibria, Energetics and Elements THURSDAY 17 JUNE 2010: Afternoon
More informationChem!stry. Assignment on Redox
Chem!stry Name: ( ) Class: Date: / / Assignment on Redox Question 1: Which one of the following elements is the most powerful reducing agent? A Aluminium B Copper C Lead D Potassium Question 2: Which of
More informationPaper Reference. Tuesday 23 January 2007 Morning Time: 1 hour 30 minutes
Centre No. Candidate No. Paper Reference(s) 6244/01 Edexcel GCE Chemistry Advanced Unit Test 4 Tuesday 23 January 2007 Morning Time: 1 hour 30 minutes Materials required for examination Nil A calculator
More informationTopic 5.1 THERMODYNAMICS. Born-Haber Cycles Solubility of Ionic Compounds in Water Entropy Changes
Topic 5.1 THERMODYNAMICS Born-Haber Cycles Solubility of Ionic Compounds in Water Entropy Changes CALCULATING ENTHALPY CHANGES a) atomisation enthalpy and bond dissociation enthalpy The enthalpy change
More informationAdvanced Subsidiary Unit 1: The Core Principles of Chemistry
Write your name here Surname Other names Pearson Edexcel International Advanced Level Centre Number Chemistry Advanced Subsidiary Unit 1: The Core Principles of Chemistry Candidate Number Thursday 14 January
More informationCHEMISTRY 110 Final EXAM Dec 17, 2012 FORM A
CEMISTRY 110 Final EXAM Dec 17, 2012 FORM A 1. Given the following reaction which of the following statements is true? Fe(s) + CuCl 2 (aq)! Cu(s) + FeCl 2 (aq) A. Iron is oxidized and copper is reduced.
More informationLondon Examinations IGCSE
Centre No. Candidate No. Paper Reference 4 3 3 5 2 H Paper Reference(s) 4335/2H London Examinations IGCSE Chemistry Paper 2H Higher Tier Wednesday 21 May 2008 Afternoon Time: 2 hours Surname Signature
More informationTHIS IS A NEW SPECIFICATION MODIFIED LANGUAGE
THIS IS A NEW SPECIFICATION ADVANCED GCE CHEMISTRY A Equilibria, Energetics and Elements F325 * OCE /30146 * Candidates answer on the Question Paper OCR Supplied Materials: Data Sheet for Chemistry A (inserted)
More informationTYPES OF CHEMICAL REACTIONS
TYPES OF CHEMICAL REACTIONS Precipitation Reactions Compounds Soluble Ionic Compounds 1. Group 1A cations and NH 4 + 2. Nitrates (NO 3 ) Acetates (CH 3 COO ) Chlorates (ClO 3 ) Perchlorates (ClO 4 ) Solubility
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 informationSuggested answers to in-text activities and unit-end exercises. Topic 16 Unit 55
Suggested answers to in-text activities and unit-end exercises In-text activities Discussion (page 117) Some possible ways for minimizing possible sources of error in the experiment: Add a slight excess
More informationREACTION RATES AND REVERSIBLE REACTIONS
NAME SCHOOL INDEX NUMBER DATE REACTION RATES AND REVERSIBLE REACTIONS 1. 1989 Q 4 P1 The graph shows the loss in total mass of a mixture of marble chips and dilute hydrochloric acid with time at 250C Loss
More informationUnit-8 Equilibrium. Rate of reaction: Consider the following chemical reactions:
Unit-8 Equilibrium Rate of reaction: Consider the following chemical reactions: 1. The solution of sodium chloride and silver nitrate when mixed, there is an instantaneous formation of a precipitate of
More information3.2.1 Energetics. Enthalpy Change. 263 minutes. 259 marks. Page 1 of 41
..1 Energetics Enthalpy Change 6 minutes 59 marks Page 1 of 41 Q1. (a) Define the term standard molar enthalpy of formation, ΔH f. (b) State Hess s law. (c) Propanone, CO, burns in oxygen as shown by the
More informationQ1. Methane and oxygen react together to produce carbon dioxide and water.
Chemistry C3 Higher Questions Part 2 Q1. Methane and oxygen react together to produce carbon dioxide and water. The methane gas will not burn in oxygen until a flame is applied, but once lit it continues
More informationAdvanced Subsidiary Unit 1: The Core Principles of Chemistry. Wednesday 11 January 2017 Morning Time: 1 hour 30 minutes
Write your name here Surname Other names Pearson Edexcel International Advanced Level Centre Number Chemistry Advanced Subsidiary Unit 1: The Core Principles of Chemistry Candidate Number Wednesday 11
More informationAS Paper 1 and 2 Kc and Equilibria
AS Paper 1 and 2 Kc and Equilibria Q1.When one mole of ammonia is heated to a given temperature, 50 per cent of the compound dissociates and the following equilibrium is established. NH 3(g) ½ N 2 (g)
More informationSIR MICHELANGELO REFALO
SIR MICELANGELO REFALO SIXT FORM alf-yearly Exam 2014 Name: CEMISTRY ADV 1 ST 3 hrs ANSWER ANY 7 QUESTIONS. All questions carry equal marks. You are reminded of the importance of clear presentation in
More informationPaper Reference. Monday 18 June 2007 Afternoon Time: 1 hour 30 minutes
Centre No. Candidate No. Paper Reference(s) 6244/01 Edexcel GCE Chemistry Advanced Unit Test 4 Monday 18 June 2007 Afternoon Time: 1 hour 30 minutes Materials required for examination Nil Candidates may
More informationNH 3(g) N 2(g) + H 2(g) What is the total number of moles of gas present in this equilibrium mixture? D 3.0 (Total 1 mark)
Q1.When one mole of ammonia is heated to a given temperature, 50% of the compound dissociates and the following equilibrium is established. NH 3(g) N 2(g) + H 2(g) What is the total number of moles of
More informationPaper Reference. Tuesday 22 January 2008 Morning Time: 1 hour 30 minutes
Centre No. Candidate No. Paper Reference(s) 6244/01 Edexcel GCE Chemistry Advanced Unit Test 4 Tuesday 22 January 2008 Morning Time: 1 hour 30 minutes Materials required for examination Nil Candidates
More informationUNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS General Certificate of Education Ordinary Level *2799730286* CHEMISTRY 5070/04 Paper 4 Alternative to Practical October/November 2007 1 hour Candidates
More informationSOLUBILITY REVIEW QUESTIONS
Solubility Problem Set 1 SOLUBILITY REVIEW QUESTIONS 1. What is the solubility of calcium sulphate in M, g/l, and g/100 ml? 2. What is the solubility of silver chromate? In a saturated solution of silver
More informationChemistry Assessment Unit AS 1
Centre Number 71 Candidate Number ADVANCED SUBSIDIARY (AS) General Certificate of Education January 2008 Chemistry Assessment Unit AS 1 assessing Module 1: General Chemistry ASC11 [ASC11] THURSDAY 17 JANUARY,
More information(a) A student carries out an investigation based on the redox systems shown in Table 5.1 below. redox system E o / V 1 Ni 2+ (aq) + 2e Ni(s) 0.
1 Redox reactions can be used to generate electrical energy from electrochemical cells. (a) A student carries out an investigation based on the redox systems shown in Table 5.1 below. redox system E o
More informationCHEM111 UNIT 1 MOLES, FORMULAE AND EQUATIONS QUESTIONS
Lesson 1 1. (a) Deduce the number of protons, neutrons and electrons in the following species: (i) 37 Cl - (ii) 1 H + (iii) 45 Sc 3+ (b) Write symbols for the following species: (i) 8 protons, 8 neutrons,
More informationinsoluble partial very soluble (< 0.1 g/100ml) solubility (> 1 g/100ml) Factors Affecting Solubility in Water
Aqueous Solutions Solubility is a relative term since all solutes will have some solubility in water. Insoluble substances simply have extremely low solubility. The solubility rules are a general set of
More informationCHEM5 (JUN13CHEM501) General Certificate of Education Advanced Level Examination June Unit 5 Energetics, Redox and Inorganic Chemistry
Centre Number Surname Candidate Number For Examiner s Use Other Names Candidate Signature Examiner s Initials General Certificate of Education Advanced Level Examination June 2013 Question 1 2 Mark Chemistry
More informationChemistry 150/151 Review Worksheet
Chemistry 150/151 Review Worksheet This worksheet serves to review concepts and calculations from first semester General Chemistry (CHM 150/151). Brief descriptions of concepts are included here. If you
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 informationStates of matter
3.1.3.4 States of matter 261 minutes 257 marks Page 1 of 30 Q1. (a) Describe the bonding in a metal. Explain why magnesium has a higher melting point than sodium. (4) (b) Why do diamond and graphite both
More informationChapter 4. The Major Classes of Chemical Reactions 4-1
Chapter 4 The Major Classes of Chemical Reactions 4-1 The Major Classes of Chemical Reactions 4.1 The Role of Water as a Solvent 4.2 Writing Equations for Aqueous Ionic Reactions 4.3 Precipitation Reactions
More informationWrite equilibrium law expressions from balanced chemical equations for heterogeneous and homogeneous systems. Include: mass action expression.
Equilibrium 1 UNIT 3: EQUILIBRIUM OUTCOMES All important vocabulary is in Italics and bold. Relate the concept of equilibrium to physical and chemical systems. Include: conditions necessary to achieve
More information1 P a g e h t t p s : / / w w w. c i e n o t e s. c o m / Chemistry (A-level)
1 P a g e h t t p s : / / w w w. c i e n o t e s. c o m / Lattice energy (Chapter 19 TB) Chemistry (A-level) Lattice energy is the enthalpy change when 1 mole of an ionic compound is formed from its gaseous
More information5. Pb(IO 3) BaCO 3 8. (NH 4) 2SO 3
Chemistry 11 Solution Chemistry II Name: Date: Block: 1. Ions in Solutions 2. Solubility Table 3. Separating Ions Ions in Solutions Ionization Equation - Represents the salt breaking apart into ions. Practice:
More information