CSEC Chemistry · May/June 2012 · Paper 2

39 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)(i)2 marksComplete Figure 1 to show how the gas was collected and measured during the experiment.
2. 1(a)(ii)3 marksUsing the same axes in Figure 2, plot a graph of the volume of gas produced versus time for the reaction with marble chips. Four of the points have already been plotted on the graph.
3. 1(a)(iii)4 marksWith reference to the volume of gas produced and the slopes along the two curves on the graph, outline ONE similarity and ONE difference in the volume of carbon dioxide produced from powdered calcium carbonate and from…
4. 1(a)(iv)2 marksWrite a balanced equation for the reaction between calcium carbonate and nitric acid.
5. 1(a)(v)3 marksCalculate the volume of gas that can be obtained from reacting 1.8 g of calcium carbonate with dilute nitric acid at R.T.P. [1 mole of gas occupies 24 000 cm³ at R.T.P. R.A.M: C = 12; O = 16; Ca = 40]
6. 1(a)(vi)1 markFrom the graph, the total volume of gas produced is 370 cm³. Suggest a possible reason for the difference in your answer obtained in (v) on page 4 and the volume of gas obtained from the graph.
7. 1(a)(vii)2 marksState TWO other factors (than the one given in (vi) above) that can affect the rate of reaction between nitric acid and calcium carbonate.
8. 1(b)(i)8 marksComplete Table 2, row 1, inference (i).
9. 1(b)(ii)8 marksComplete Table 2, row 2, observation (ii).
10. 1(b)(iii)8 marksComplete Table 2, row 3, inference (iii).
11. 1(b)(iv)8 marksComplete Table 2, row 4, inference (iv).
12. 1(b)(v)8 marksComplete Table 2, row 4, observation (v).
13. 2(a)1 markDeduce the oxidation state of sulphur in CuSO4.
14. 2(b)1 markAt the anode, the hydroxide ions are discharged in preference to the sulphate ions. State a reason for this.
15. 2(c)2 marksWrite a balanced equation for the reaction at the anode.
16. 2(d)1 markFrom the equation written in (c) above, state whether the reaction at the anode is oxidation or reduction. Give an explanation for your answer.
17. 2(e)2 marksState TWO changes that occur in the electrolyte.
18. 2(f)4 marksDetermine the mass of copper (in grams) which will be deposited at the cathode when 5A of current passes through the electrolytic cell for half an hour. [R.A.M. Cu = 64; 1 Faraday = 96 500 C]
19. 2(g)3 marksIndicate below how the apparatus in Figure 3 can be modified to obtain pure copper from impure copper. If no modification is required write “no modification required" in the relevant space. Anode: Cathode: Electrolyte:
20. 3(a)(i)2 marksWrite the names of the homologous series to which A and B belong. Homologous series for A: Homologous series for B:
21. 3(a)(ii)2 marksWrite the general formulae for EACH homologous series named in (i) above. General formula for homologous series of A: General formula for homologous series of B:
22. 3(a)(iii)a)1 markState ONE necessary condition for B to react with chlorine.
23. 3(a)(iii)b)4 marksDraw the FULLY displayed structures of the organic products for the reactions of A and B with chlorine.
24. 3(b)(i)1 markState the role of K2Cr2O7 in the conversion of D to E.
25. 3(b)(ii)2 marksWrite a balanced equation for the reaction of E with solid magnesium oxide (MgO).
26. 3(b)(iii)2 marksDescribe ONE chemical test that could be used to identify the gas given off from the reaction of Compound E with solid calcium carbonate. Include the expected observation.
27. 3(b)(iv)1 markState the name of the homologous series to which Compound J belongs.
28. 4(a)4 marksState TWO other uses of radioisotopes and explain the importance of EACH.
29. 4(b)(i)4 marksOutline the criteria for placing elements in the Periodic Table. Hence, state the appropriate group and period for EACH of the elements P, Q, R and S.
30. 4(b)(ii)4 marksElements P and Q react together to form a compound. Deduce whether this compound is ionic or covalent. Use 'dot cross' diagrams to show the bonding in the compound formed and write its formula.
31. 4(b)(iii)3 marksCompare the reactivity of EACH of elements Q and S with dilute hydrochloric acid. Write a balanced equation for EITHER of these reactions with dilute hydrochloric acid.
32. 5(a)3 marksState the property of metals that is responsible for corrosion and describe the process of corrosion.
33. 5(b)3 marksWrite THREE relevant chemical equations for the corrosion of iron.
34. 5(c)7 marksExplain why the corrosion of aluminium is beneficial while that of iron is not. In your answer, you should refer to the products of corrosion and their properties.
35. 5(d)2 marksAluminium is widely used to make cookware. Explain why it is NOT advisable to use aluminium pots to prepare acidic foods.
36. 6(a)6 marksOutline THREE properties of water and relate them to its function in maintaining life on earth.
37. 6(b)(i)1 markState the meaning of the term 'hard water'.
38. 6(b)(ii)4 marksDescribe ONE way in which water can be softened. Include a chemical equation with state symbols in your description.
39. 6(c)4 marksIt is important that communities and individual households play a part in the management and preservation of the environment. Suggest FOUR practical ways in which households or communities can manage or preserve the…