CAPE Chemistry Unit 1 · May/June 2024 · Paper 2

43 questions and parts from this paper. Open one to see it in full, then practise it on Quelpr and get it marked against the mark scheme.

1. 1(a)1 markName the series of lines produced by these electron transitions.
2. 1(b)2 marksDraw diagrams (including the axes) to show the shapes of the s and p orbitals.
3. 1(c)2 marksState what is meant by the term 'hybridization'.
4. 1(d)2 marksBenzene exhibits resonance structures. Explain what is meant by 'resonance'.
5. 1(e)(i)3 marksState THREE criteria used in the valence shell electron pair repulsion (VSEPR) theory to determine the shapes of molecules and ions.
6. 1(e)(ii)a)2 marksUse the criteria in (e)(i) to determine the shape and bond angles in the beryllium chloride molecule.
7. 1(e)(ii)b)2 marksUse the criteria in (e)(i) to determine the shape and bond angles in the methyl anion, CH3^-.
8. 1(e)(iii)1 markDraw a diagram to show the shape of the methyl anion, CH3^-.
9. 1(f)(i)1 markCalculate the number of moles of potassium manganate(VII) used in the titration.
10. 1(f)(ii)1 markUsing the equation 2 MnO4^-(aq) + 5 NO2^-(aq) + 6 H^+(aq) -> 2 Mn^2+(aq) + 5 NO3^-(aq) + 3 H2O(l), deduce the number of moles of KNO2 present in the titre volume.
11. 1(f)(iii)1 markCalculate the number of moles of KNO2 that was present in the residue from the decomposition of Sample A.
12. 1(f)(iv)2 marksCalculate the mass of KNO2 present in the residue from Sample A.
13. 1(f)(v)3 marksUsing the equation for the decomposition of KNO3, determine the mass of KNO2 formed if 6.20 g KNO3 were completely decomposed.
14. 1(f)(vi)2 marksUsing the results from (f)(iv) and (v), calculate the percentage of KNO2 formed.
15. 1(f)(vii)5 marksOutline the experimental steps taken in the laboratory to prepare the 0.02 mol dm^-3 potassium manganate(VII) solution used for this titration.
16. 2(a)2 marksWhat is meant by the term 'dynamic equilibrium'?
17. 2(b)(i)1 markWrite an expression for the equilibrium constant of the reverse reaction.
18. 2(b)(ii)1 markState the numerical value of the equilibrium constant for the reverse reaction based on the expression in (b)(i).
19. 2(c)2 marksState Le Chatelier's principle.
20. 2(d)(i)2 marksUse Le Chatelier's principle to predict and explain the effect of increasing the pressure on Equilibrium A.
21. 2(d)(ii)2 marksUse Le Chatelier's principle to predict and explain the effect of decreasing the temperature on Equilibrium A.
22. 2(d)(iii)2 marksUse Le Chatelier's principle to predict and explain the effect of increasing [H^+(aq)] on Equilibrium B.
23. 2(e)(i)2 marksDefine the term 'buffer solution'.
24. 2(e)(ii)3 marksGiven that Ka for the weak acid = 7.4 * 10^-4 mol dm^-3, calculate the pH of the buffer solution.
25. 2(f)5 marksOutline the experimental procedure which can be used to prepare a sample of the buffer solution in (e). Include tests used to confirm a buffer solution was formed.
26. 2(g)4 marksWith the aid of equations, explain how a solution of ammonium sulfate and ammonia can control pH.
27. 2(h)2 marksDefine the term 'half-life'.
28. 2(i)2 marksUsing a Boltzmann distribution curve, show how a catalyst affects the rate of a chemical reaction.
29. 3(a)(i)3 marksWrite the formulae of the oxides of the elements of the third period, from sodium to sulfur.
30. 3(a)(ii)3 marksExplain the difference in the oxidation number in the oxides of sodium and aluminium.
31. 3(a)(iii)a)1 markState the type of bond present in magnesium chloride.
32. 3(a)(iii)b)1 markState the type of bond present in silicon chloride.
33. 3(a)(iii)c)1 markState the type of bond present in phosphorus(III) chloride.
34. 3(a)(iv)4 marksWith the aid of an equation, describe the reaction of silicon chloride in water.
35. 3(b)(i)2 marksDefine the term 'ligand'.
36. 3(b)(ii)1 markWrite the formula of the complex formed between X^3+ and six hydroxide ligands.
37. 3(b)(iii)1 markState the shape of the complex formed.
38. 3(b)(iv)2 marksUsing a suitable diagram, illustrate your answer in (b)(iii).
39. 3(b)(v)2 marksState what is meant by the term 'coordination number', in reference to a complex ion.
40. 3(c)(i)2 marksState the expected observation for the addition of concentrated hydrochloric acid to aqueous copper(II) sulfate.
41. 3(c)(ii)3 marksWrite an equation for the reaction which occurs between aqueous copper(II) ions and concentrated hydrochloric acid, and identify the species with the higher Kstab (stability constant) value.
42. 3(d)(i)2 marksDescribe the changes which occur at the end point of the titration.
43. 3(d)(ii)2 marksWrite the formula and state the colour of the species formed from the oxidation of Fe^2+ ions.