CSEC Chemistry · May/June 2018 · 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)1 markDefine 'rate of reaction'.
2. 1(b)(i)2 marksWrite a balanced chemical equation for the reaction between calcium carbonate and hydrochloric acid.
3. 1(b)(ii)3 marksCalculate the volume of carbon dioxide that would be produced at RTP from 1.0 g of CaCO₃ chips. [RMM: CaCO₃ = 100; 1 mole of a gas occupies 24 000 cm³ at RTP.]
4. 1(c)(i)3 marksFrom the stopwatches displayed in Figure 1 on page 4, record the times taken for the carbon dioxide gas to be collected in the appropriate spaces in Table 1. The time taken for Test 1 has already been recorded.
5. 1(c)(ii)4 marksCalculate the reciprocal times (1/time) and record them to 3 decimal places in the appropriate spaces in Table 1. The reciprocal time for Test 1 has already been calculated.
6. 1(c)(iii)5 marksUsing the axes provided in Figure 2 on page 7, plot a graph of reciprocal time versus temperature for Tests 1–6. Draw the best curve through the points.
7. 1(d)(i)1 markBased on the graph drawn in (c)(iii) on page 7, deduce the effect that temperature has on the rate of reaction.
8. 1(d)(ii)2 marksState TWO reasons that account for the observed effect, given in (d)(i), of temperature on the rate of reaction.
9. 1(e)2 marksUse the graph drawn on page 7 to determine the value of the reciprocal time that would have been obtained if the experiment was carried out at 40 °C.
10. 1(f)2 marksDescribe a confirmatory test for carbon dioxide.
11. 2(a)(i)2 marksDefine 'isotopes'.
12. 2(a)(ii)2 marksHence, show by calculation that chlorine-35 and chlorine-37 are isotopes.
13. 2(b)2 marksState TWO uses of radioisotopes.
14. 2(c)(i)2 marksWrite a balanced chemical IONIC equation for the reaction that is responsible for the colour change.
15. 2(c)(ii)2 marksDescribe the colour change that the student observed.
16. 2(d)(i)2 marksWrite a balanced chemical equation, with state symbols, for the burning of sulfur in air.
17. 2(d)(ii)1 markState ONE use of sulfur.
18. 2(d)(iii)2 marksWrite a balanced chemical equation, with state symbols, for the reaction of magnesium with sulfur.
19. 3(a)2 marksState the homologous series to which EACH compound belongs.
20. 3(b)2 marksState one use EACH of Compound X and Compound Y.
21. 3(c)4 marksDraw the FULLY DISPLAYED formulae to show the structure of Compound X and Compound Y.
22. 3(d)(i)2 marksDraw the structure of the alcohol formed from Compound Y.
23. 3(d)(ii)2 marksState the reagents and reaction conditions for the conversion of Compound Y to the alcohol.
24. 3(e)1 markState the name of the ester formed.
25. 3(f)2 marksWrite the full equation for the reaction between ethanol and ethanoic acid.
26. 4(a)2 marksDefine 'electrolysis'.
27. 4(b)(i)2 marksSolid sodium chloride
28. 4(b)(ii)2 marks1 mol dm⁻³ hydrochloric acid
29. 4(b)(iii)2 marksEthanol
30. 4(b)(iv)2 marksA bar of lead touching the electrodes
31. 4(c)5 marksA sample of molten lead bromide, PbBr₂, is electrolysed for three minutes with a current of 6 amperes. Calculate the mass of lead that is deposited at the cathode, given that two moles of electrons are required to…
32. 5(a)5 marksDescribe the process of fermentation. In your description, identify the raw materials and products, and write a relevant chemical equation.
33. 5(b)4 marksBriefly describe the soap-making process, stating the necessary reagents and conditions. Based on the structure of the fat molecule shown above, draw the structure of the soap that would be formed during the…
34. 5(c)(i)4 marksBased on the following diagrams showing the partial structure of a polymer, deduce the type of polymer shown, and the type of polymerization reaction that took place in EACH case.
35. 5(c)(ii)2 marksDraw the structure of the monomer used to form Polymer CC.
36. 6(a)(i)5 marksDiscuss the importance of magnesium in plant health, and explain how a magnesium deficiency can result in the low yield of tomatoes.
37. 6(a)(ii)2 marksState ONE other metal ion which is important to plant health and state the result of its deficiency.
38. 6(b)5 marksIdentify ONE metal and ONE nonmetal whose compounds were present in car exhaust fumes. Discuss the effect of these compounds on human health and the environment.
39. 6(c)3 marksDefine 'green chemistry' and discuss the measures that have been taken to produce a 'greener' automotive fuel.