CAPE Chemistry Unit 2 · 2013 · Paper 2

52 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 marksDraw the chemical structures of the products formed at P from the alkaline hydrolysis of Compound X.
2. 1(a)(ii)2 marksDraw the chemical structures of the products formed at Q from the transesterification reaction of Compound X with methanol and sodium hydroxide.
3. 1(a)(iii)a)1 markIdentify the process which leads to the formation of the products at P.
4. 1(a)(iii)b)1 markIdentify the process which leads to the formation of the products at Q.
5. 1(a)(iv)a)1 markState a use of the non-alcoholic product formed at P.
6. 1(a)(iv)b)1 markState a use of the non-alcoholic product formed at Q.
7. 1(b)(i)a)1 markState the observation when 1.0 cm³ of Z is treated with 2,4-DNPH, given the inference that Z is a carbonyl compound.
8. 1(b)(i)b)1 markState the observation when 1.0 cm³ of Z is heated with acidified KMnO4, given the inference that Z reduces KMnO4.
9. 1(b)(i)c)1 markState the inference when 1.0 cm³ of Z gives a silver mirror with Tollen's reagent.
10. 1(b)(i)d)1 markState the inference when 1.0 cm³ of Z shows no reaction with Fehling's solution.
11. 1(b)(ii)1 markDraw the likely chemical structure for Compound Z based on the observations in Table 1.
12. 1(c)2 marksOutline the mechanism for the reaction between a carbonyl compound and HCN, using curved arrows to show electron movement.
13. 2(a)2 marksState two molecular characteristics required for a molecule to be suitable for analysis by infrared (IR) spectroscopy.
14. 2(b)2 marksGive two examples of practical applications of IR spectroscopy.
15. 2(c)(i)a)1 markIdentify Compound A from its IR spectrum shown in Figure 2.
16. 2(c)(i)b)1 markJustify your identification of Compound A by indicating which absorption band on the spectrum was used and specifying the functional group responsible.
17. 2(c)(ii)a)1 markIdentify Compound B from its IR spectrum shown in Figure 3.
18. 2(c)(ii)b)1 markJustify your identification of Compound B by indicating which absorption band on the spectrum was used and specifying the functional group responsible.
19. 2(c)(iii)a)1 markIdentify Compound C from its IR spectrum shown in Figure 4.
20. 2(c)(iii)b)1 markJustify your identification of Compound C by indicating which absorption band on the spectrum was used and specifying the functional group responsible.
21. 2(d)(i)4 marksDescribe four steps involved in preparing and analysing a solid sample using IR spectroscopy.
22. 2(d)(ii)1 markExplain why the sample plates used in IR spectroscopy are made of NaCl.
23. 3(a)(i)1 markState the process that may have led to the transport of pollutants into the stream.
24. 3(a)(ii)2 marksIdentify two sources of pollutants (other than fertilizers) most likely present in the stream.
25. 3(b)(i)2 marksDescribe a laboratory test to identify the presence of nitrates, stating the reagents used and the expected observations.
26. 3(b)(ii)2 marksDescribe a laboratory test to identify the presence of phosphates, stating the reagents used and the expected observations.
27. 3(c)(i)2 marksState two ways by which dissolved oxygen enters natural waterways.
28. 3(c)(ii)2 marksExplain how the process of eutrophication causes a decline in water quality.
29. 3(c)(iii)2 marksExplain why dissolved oxygen must be removed from water prior to use in industrial boilers and pipelines.
30. 3(d)2 marksState two main steps involved in municipal water treatment to produce potable water.
31. 4(a)(i)1 markState the reagent needed to convert phenol into sodium phenoxide (reaction (i)).
32. 4(a)(ii)1 markDraw the structure of the organic product formed when phenol reacts with Br2(aq) (reaction (ii)).
33. 4(a)(iii)1 markIdentify the reagent needed to convert phenol into phenyl propanoate (reaction (iii)).
34. 4(b)(i)3 marksState the reagents and conditions required for each of Steps I, II, and III.
35. 4(b)(ii)3 marksOutline the electrophilic substitution mechanism for the nitration of benzene in Step I, using curved arrows to show electron movements.
36. 4(b)(iii)1 markState the name of the reaction mechanism outlined in (b)(ii).
37. 4(b)(iv)1 markExplain why the bromo substituent enters the 3-position (meta-position) relative to the nitro group in Step II.
38. 4(c)(i)1 markArrange benzene, nitrobenzene, and methylbenzene in order of increasing ease of reactivity towards electrophilic chlorination.
39. 4(c)(ii)3 marksDraw the major mono-substituted aromatic chlorinated product formed from the reaction of chlorine with benzene, nitrobenzene, and methylbenzene, respectively.
40. 5(a)2 marksDefine the term 'partition coefficient'.
41. 5(b)4 marksWhen butanedioic acid was shaken with a mixture of water and ether, 10 cm³ of water contained 0.854 g of the acid while a similar volume (10 cm³) of ether contained 0.159 g. In a separate experiment, 10 cm³ of water and…
42. 5(c)(i)1 markSuggest an appropriate separation technique to separate eucalyptus oil from an aqueous suspension of its leaves.
43. 5(c)(ii)1 markSuggest an appropriate separation technique to isolate penicillin (organic solid) from an aqueous solution.
44. 5(c)(iii)1 markSuggest an appropriate separation technique to separate the components of a coal tar residue.
45. 5(c)(iv)1 markSuggest an appropriate separation technique to purify ethoxyethane from an impure source.
46. 5(d)5 marksUse the boiling point-composition phase diagram in Figure 6 to explain the principles of fractional distillation, starting with a liquid mixture of composition x.
47. 6(a)7 marksDescribe the Bayer process for extracting aluminium oxide from bauxite ore. Include two balanced chemical equations in your description.
48. 6(b)(i)1 markName an environmental pollutant produced as a by-product during the extraction of alumina from bauxite.
49. 6(b)(ii)2 marksDescribe two environmental consequences caused by the named pollutant in (b)(i).
50. 6(c)(i)2 marksWrite balanced ionic half-equations for the reactions occurring at the cathode and the anode during the Hall-Héroult electrolytic process.
51. 6(c)(ii)a)1 markOutline one reason for the high economic/energy cost associated with the extraction of aluminium by electrolysis.
52. 6(c)(ii)b)2 marksSuggest two reasons why the recycling of aluminium is important.