CSEC Chemistry · January 2011 · Paper 2

41 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 marksDifferentiate between a 'strong acid' and a 'weak acid'.
2. 1(a)(ii)1 markSuggest ONE other base that could be used instead of NaOH.
3. 1(a)(iii)2 marksUsing the thermometer readings in Figure 1, complete Table 1 by recording the temperature for the addition of 10 cm³ and 20 cm³ of the H₂SO₄.
4. 1(a)(iv)3 marksPlot the points for temperature against volume of acid added using the axes on page 3.
5. 1(a)(v)3 marksDraw the TWO lines of best fit through the points in (iv) above where the temperature is increasing and where the temperature is decreasing and hence determine the end point of the reaction. Volume of H₂SO₄ at end point
6. 1(a)(vi)2 marksWrite a balanced equation for this reaction.
7. 1(a)(vii)1 markCalculate the number of moles of NaOH used in the reaction.
8. 1(a)(viii)2 marksCalculate the concentration of H₂SO₄ in mol dm⁻³.
9. 1(b)(i)1 markIdentify Solution X.
10. 1(b)(ii)2 marksIdentify ONE flaw in the procedure that Paul used for carrying out EACH test.
11. 1(b)(iii)2 marksWrite a balanced equation for the reaction occurring in Tube 1. Balanced equation:
12. 1(b)(iv)4 marksExplain why nitric acid instead of sulphuric acid is used in the experiment in Tube 1 in order to obtain a positive test result.
13. 2(a)(i)2 marksWhat changes would be observed in Beakers A and B over a 24-hour period?
14. 2(a)(ii)1 markHow do the changes in Beaker A differ from that in Beaker B?
15. 2(a)(iii)3 marksAccount for any differences in the observations in (a) (ii) above.
16. 2(b)(i)1 markState whether the process in Experiment III is exothermic or endothermic. The process is
17. 2(b)(ii)3 marksDraw a labelled energy profile diagram to show the heat changes involved in Experiment III.
18. 2(b)(iii)2 marksCalculate the heat change when 8 g of ammonium nitrate is dissolved in 50 cm³ of water. [Relative Atomic Mass: N = 14; H = 1; O = 16; the specific heat capacity of the solution is 4.2 kJ kg⁻¹ K⁻¹; density of water is…
19. 2(b)(iv)1 markState ONE assumption necessary in your calculation in (b) (iii) above.
20. 2(b)(v)2 marksFrom your answer to (b) (iii), calculate the heat change when 1 mole of ammonium nitrate dissolves in water.
21. 3(a)4 marksDraw the FULLY displayed structures and state the names of BOTH compounds. Compound A Name: Compound B Name:
22. 3(b)(i)1 markState the observation for this reaction. Observation:
23. 3(b)(ii)2 marksWrite a chemical equation for this reaction. Equation:
24. 3(b)(iii)2 marksDraw the FULLY displayed structure of the product in the equation in (b) (ii) above and state the name of this product. Structure Name:
25. 3(c)(i)3 marksWrite the names of the homologous series to which EACH of these three compounds belongs. Compound X: Compound Y: Compound Z:
26. 3(c)(ii)2 marksState which TWO of these compounds are soluble in water, and give a reason for your choice. TWO compounds: Reason:
27. 4(a)4 marksOutline what happens in EACH step.
28. 4(b)(i)2 marksOutline the reason for the change in atomic radius from magnesium to barium.
29. 4(b)(ii)2 marksBarium reacts more readily with water than magnesium does. With reference to the data in Table 2, explain this observation.
30. 4(c)(i)2 marksState whether a reaction would take place in EACH case.
31. 4(c)(ii)2 marksWrite a balanced equation, where appropriate, for the reaction occurring in (c) (i) above.
32. 4(d)(i)2 marksDescribe a test that can be used to identify the solution formed with sulphur dioxide.
33. 4(d)(ii)1 markWrite a balanced equation to support the use of this test.
34. 5(a)(i)8 marksDescribe the processes involved in converting sulphur to sulphur trioxide. In your response, a) identify A from Figure 5 b) include TWO balanced chemical equations for the reactions taking place at Steps I and II c)…
35. 5(a)(ii)2 marksExplain why concentrated H₂SO₄ is used instead of pure water in Step III of Figure 5.
36. 5(a)(iii)2 marksWhen sulphur trioxide gets into the atmosphere, it can form acid rain which can destroy buildings made from limestone. Write an ionic equation which BEST represents the chemical reaction taking place when acid rain…
37. 5(b)3 marksWith reference to this figure, explain why diamond is used for cutting and graphite is not.
38. 6(a)1 markIdentify ONE OTHER major constituent of wheat flour.
39. 6(b)(i)3 marksState ONE similarity and ONE difference in the way they act as raising agents.
40. 6(b)(ii)6 marksExplain how the action of yeast during bread-making causes the dough to rise. Include TWO chemical equations and the reaction conditions.
41. 6(c)5 marksSuggest a possible explanation for this practice. Write ONE chemical equation to support this practice.