CSEC Chemistry · May/June 2011 · 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)(i)2 marksDefine the term 'electrolysis'.
2. 1(a)(ii)2 marksState TWO differences between the 'anode' and the 'cathode'.
3. 1(a)(iii)3 marksDraw a diagram to show a circuit for carrying out this investigation. Label the cathode and the electrolyte.
4. 1(a)(iv)2 marksComplete Table 1 by recording the mass of the cathode after 10 minutes and 20 minutes and the mass of copper deposited after 15 and 25 minutes.
5. 1(a)(ix)2 marksCalculate the number of moles of copper that would be formed.
6. 1(a)(v)3 marksPlot a graph of actual mass of copper deposited versus time using the axes in Figure 1 on page 5.
7. 1(a)(vi)1 markUse the graph to predict the mass of copper that would be deposited after 28 minutes.
8. 1(a)(vii)2 marksWrite an ionic equation to represent the reaction at the cathode.
9. 1(a)(viii)2 marksCalculate the quantity of electricity that passed through the copper sulphate solution when 0.2 A of current flowed for 20 minutes. (Quantity of electricity = current × time; 1 F = 96 500 C)
10. 1(a)(x)1 markCalculate the mass of copper that would be formed. (Relative atomic mass: Cu = 64; 1 F = 96 500 C)
11. 1(a)(xi)1 markSuggest a reason for the difference between the mass of copper obtained in (x) above and that recorded in Table 1.
12. 1(a)(xii)1 markThe circuit used in this experiment was modified by replacing the copper electrodes with graphite electrodes. State ONE difference in the reaction at the anode when graphite electrodes are used.
13. 1(b)3 marksComplete Table 2 by writing the observations for the tests carried out on Salt S.
14. 2(a)6 marksComplete Table 3 to show the structure and conductivity of EACH solid substance listed. The first one is done as an example.
15. 2(b)(i)1 markWhich of the two compounds, magnesium chloride or potassium nitrate, has the GREATER solubility at 15 °C?
16. 2(b)(ii)2 marksCalculate the mass of potassium nitrate that would be deposited when its saturated solution is cooled from 80 °C to 20 °C.
17. 2(b)(iii)1 markDetermine the temperature at which the solubilities of magnesium chloride and potassium nitrate are equal.
18. 2(c)2 marksDraw the bonding diagram to show how magnesium combines with chlorine to form magnesium chloride.
19. 2(d)3 marksBased on the use and purpose of solid air fresheners, would you classify them as having simple molecular, giant covalent, or ionic lattices? Explain your answer.
20. 3(a)(i)2 marksDefine 'anaerobic fermentation'.
21. 3(a)(ii)1 markGive ONE reason why high temperatures are NOT suitable for anaerobic fermentation.
22. 3(b)4 marksDraw FULLY displayed structures of the hydrolysis products, A and B.
23. 3(c)2 marksName ONE by-product of the saponification of fats and oils, and state ONE disadvantage of synthetic cleaning agents over soaps.
24. 3(d)(i)2 marksDraw the structure of the polymer formed from propene. Use THREE units of the monomer to demonstrate your answer.
25. 3(d)(ii)1 markWhat type of polymerisation would the 3-amino propanoic acid undergo? State the general name for the type of polymer formed from 3-amino propanoic acid.
26. 3(d)(iii)2 marksOutline a chemical test that can be used to distinguish between propene and its polymer.
27. 4(a)(i)10 marksState the expected observations and write balanced chemical equations to explain any reactions that take place. Give the chemical test(s) which may be used to identify any gases produced. Record your answer in a table…
28. 4(a)(ii)2 marksOutline a method that can be used to obtain a solid sample of a salt where EITHER the K₂CO₃ OR Zn completely reacts with the dilute nitric acid as described in (a) (i) above.
29. 4(b)3 marksExplain the observations expected for EACH part.
30. 5(a)(i)2 marksUse the information given to place Metal X, copper and iron in the order in which they will appear in the reactivity series, starting with the MOST reactive.
31. 5(a)(ii)2 marksWrite an ionic equation for the reaction between Metal X and copper(II) sulphate. Include the relevant state symbols.
32. 5(b)(i)1 markWhat is an alloy?
33. 5(b)(ii)1 markName the alloy of copper and aluminium.
34. 5(b)(iii)3 marksState TWO properties of aluminium that make the alloy in (b) (ii) a good choice to be used in the manufacture of aircraft.
35. 5(b)(iv)2 marksList TWO other uses of this alloy.
36. 5(c)4 marksCalculate the mass of copper produced if 0.12 dm³ of nitrogen is produced at room temperature and pressure (rtp). (Relative atomic mass of Cu = 64; One mole of gas occupies 24 dm³ at rtp.)
37. 6(a)2 marksSuggest a reason for this.
38. 6(b)(i)3 marksExplain how natural OR commercial tenderizers work when used to tenderize meat.
39. 6(b)(ii)2 marksList ONE advantage and ONE disadvantage of using commercial tenderizers over natural tenderizers.
40. 6(b)(iii)2 marksBaking soda, NaHCO₃, can also be used to tenderize meat. Suggest why this is possible.
41. 6(c)(i)1 markWhat colour change would you expect at the end point in BOTH cases?
42. 6(c)(ii)3 marksWhich sample, A or B, would require the LARGER volume of iodine? Explain your answer.
43. 6(c)(iii)2 marksWith reference to the oxidation number of iodine, explain whether vitamin C is acting as an oxidizing or a reducing agent when it reacts with iodine.