CSEC Chemistry · January 2018 · Paper 2

46 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)9 marksComplete Table 1 by recording the titration results obtained from the experiment in Figure 1.
2. 1(a)(ii)1 markCalculate the average volume of solution M used in the titration.
3. 1(a)(iii)2 marksCalculate the concentration of hydrochloric acid in solution M, in mol dm⁻³. (Relative atomic mass: H = 1; Cl = 35.5)
4. 1(a)(iv)1 markCalculate the number of moles of hydrochloric acid used in the titration.
5. 1(a)(v)1 markWrite a balanced equation for the reaction between the hydrochloric acid and sodium hydroxide solutions.
6. 1(a)(vi)2 marksDetermine the number of moles of sodium hydroxide in the 25 cm³ of solution used.
7. 1(a)(vii)2 marksCalculate the concentration of sodium hydroxide, in g dm⁻³. (Molar mass of sodium hydroxide = 40 g mol⁻¹)
8. 1(b)(i)1 markIdentify the forces that exist in a ‘molecular solid'.
9. 1(b)(ii)2 marksSodium chloride, another solid, has a higher melting and boiling point than stearic acid. Explain why this is so.
10. 1(b)(iii)4 marksUsing the axes provided in Figure 2 on page 9, plot a graph of temperature against time from the information in Table 2. One point has already been plotted. Draw the best fit curve through your points.
11. 2(a)(i)1 markDefine the terms 'acid' and 'alkali'.
12. 2(a)(ii)1 markDefine the terms 'acid salts' and 'normal salts'.
13. 2(a)(iii)1 markState the molecular formula for the normal salt formed from the reaction between phosphoric acid and sodium hydroxide.
14. 2(a)(iv)2 marksWrite a balanced equation to show the formation of the normal salt stated in (a)(iii).
15. 2(a)(v)1 markState the molecular formula for an acid salt formed from the reaction between phosphoric acid and sodium hydroxide.
16. 2(a)(vi)2 marksWrite a balanced equation to show the formation of the acid salt stated in (a)(v).
17. 2(b)1 markWhich of the two acids is stronger?
18. 2(c)(i)2 marksName TWO acids present in orange juice.
19. 2(c)(ii)1 markState the type of chemical reaction that takes place in the treatment of excess stomach acid.
20. 2(c)(iii)1 markHence, name ONE substance that can be used to treat excess stomach acid.
21. 3(a)(i)2 marksDraw the FULLY DISPLAYED structure of ethene.
22. 3(a)(ii)2 marksDraw the FULLY DISPLAYED structure of the 1,2-dichloroethane.
23. 3(a)(iii)1 markIs the halogenation of ethene an addition or substitution reaction?
24. 3(b)(i)4 marksWrite balanced chemical equations to show EACH step in the formation of dichloromethane.
25. 3(b)(ii)1 markIs the halogenation of methane an addition or substitution reaction?
26. 3(c)(i)1 markDefine the term 'polymer.'
27. 3(c)(ii)1 markDefine what is meant by ‘addition polymerization.'
28. 3(c)(iii)1 markState ONE use of EACH of the following polymers: Polyvinyl chloride, Teflon, Poly(ethene).
29. 4(a)(i)2 marksDistinguish between the terms 'endothermic' and 'exothermic.'
30. 4(a)(ii)1 markGenerally, when chemical reactions take place, existing bonds are broken and new bonds are formed. Classify bond making AND bond breaking as either endothermic or exothermic processes.
31. 4(b)(i)1 markCalculate the number of moles of KNO₃ used in the experiment. (RMM: KNO₃ = 101)
32. 4(b)(ii)2 marksCalculate the heat change for the reaction. Specific heat capacity of water = 4.2 J g⁻¹ °C⁻¹; Heat change = m × c × △T; Density of water = 1 g cm⁻³
33. 4(b)(iii)1 markCalculate the enthalpy change for 1 mole of potassium nitrate.
34. 4(b)(iv)4 marksList TWO pieces of apparatus necessary to conduct the experiment in a school laboratory. State how EACH piece of apparatus is used.
35. 4(b)(v)3 marksDraw a labelled energy profile diagram to represent the enthalpy change for the reaction. On your diagram, indicate the sign of △H for the reaction.
36. 5(a)(i)1 markState the homologous series to which ethyl pentanoate belongs.
37. 5(a)(ii)3 marksDraw the FULLY DISPLAYED structure of ethyl pentanoate and circle the functional group.
38. 5(a)(iii)2 marksWrite the molecular formulae for the alcohol and carboxylic acid that will react to produce ethyl pentanoate.
39. 5(a)(iv)1 markName the catalyst involved in the reaction between the alcohol and carboxylic acid stated in (c)(iii).
40. 5(a)(v)2 marksExplain why an ester has low solubility in water whereas a simple alcohol is very soluble in water.
41. 5(b)4 marksState the reaction condition and reagent used for the alkaline hydrolysis of ethyl ethanoate. Hence, write a balanced chemical equation for this reaction.
42. 5(c)2 marksCommercial soaps are usually manufactured using natural esters. Name the process used to make soap and state ONE source of these natural esters.
43. 6(a)4 marksList FOUR unique properties of water as it relates to the human body.
44. 6(b)2 marksWater exists in liquid, solid and gaseous states. Describe a laboratory test for water vapour.
45. 6(c)3 marksWrite a balanced chemical equation, including state symbols, to show the removal of temporary hardness from water using this treatment.
46. 6(d)6 marksPredict the ions that will migrate to the anode and cathode during the electrolysis of dilute sulfuric acid (acidified water). Write a balanced chemical equation, including state symbols, for the electrolysis of dilute…