CAPE Chemistry Unit 2 · May/June 2022 · Paper 2

33 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 marksState the reagents and conditions for reaction I (from A to B).
2. 1(a)(ii)2 marksState the reagents and conditions for reaction II (from A to C).
3. 1(a)(iii)4 marksDraw the displayed structures and provide names for EACH of the following compounds: Compound D, Compound E.
4. 1(b)(i)2 marksWrite an expression for the Kₐ of chloroethanoic acid.
5. 1(b)(ii)1 markWrite an expression to show how pKₐ is derived from Kₐ.
6. 1(c)(i)4 marksComplete Table 1 above by correctly inserting the pKₐ value of EACH compound from the following list of values: 1.48, 0.70, 4.76 and 2.86.
7. 1(c)(ii)5 marksGive reasons for your assignments in (c)(i).
8. 1(d)4 marksAccount for the fact that the pKₐ of phenylamine is greater than that of ethylamine.
9. 1(e)(i)2 marksDraw the structure of the monomer used to form polymer P and name the type of polymerization involved.
10. 1(e)(ii)3 marksDraw the structures of the two compounds which react to form the polymer Q and name the type of polymerization involved.
11. 1(e)(iii)1 markIdentify a compound which in aqueous solution will break down polymer Q but not polymer P.
12. 2(a)4 marksExplain how a mass spectrometer works to obtain a mass spectrum of a molecule.
13. 2(b)(i)2 marksState the m/z ratio of the M⁺ and M+2 peak?
14. 2(b)(ii)3 marksDeduce the formula of the fragments at m/z ratio of 43, 107 and 109.
15. 2(b)(iii)3 marksDetermine the formula of the M⁺ and M+2 molecular ion species and name the haloalkane.
16. 2(c)(i)1 markName the process by which TLC separates α-amino acids.
17. 2(c)(ii)2 marksThe chromatogram was treated to show the positions of the separated α-amino acids. Explain how the student could analyse the chromatogram to identify the three α-amino acids that were present.
18. 2(c)(iii)2 marksSeveral α-amino acids have structures that are very similar. Suggest why this could cause problems when using TLC to analyse mixtures of α-amino acids.
19. 2(d)(i)5 marksOutline a series of steps indicating how this mixture can be separated, and the two components recovered, by the process of solvent extraction.
20. 2(d)(ii)1 markState what is meant by the term 'partition coefficient'.
21. 2(d)(iii)2 marksIf iodine is shaken with 100 cm³ of water and 100 cm³ of an organic solvent, the concentration of iodine in the water layer is 4.0 × 10⁻³ mol dm⁻³ and in the organic solvent is 1.0 × 10⁻² mol dm⁻³. Calculate the…
22. 2(d)(iv)5 marksThe aqueous layer is separated and shaken with 50 cm³ of the pure organic solvent. Determine the concentration of iodine in the organic solvent at equilibrium in mol dm⁻³? Show ALL working.
23. 3(a)4 marksComplete Table 2 by inserting the missing information in the blank spaces.
24. 3(b)(i)2 marksDefine the term 'catalytic cracking'.
25. 3(b)(ii)2 marksWrite a balanced equation to show the products of the cracking of decane, C₁₀H₂₂.
26. 3(b)(iii)3 marksExplain the principles involved in the fractional distillation of crude oil.
27. 3(b)(iv)3 marksExplain how ONE adverse effect of the petroleum industry can impact the environment.
28. 3(c)(i)3 marksDefine EACH of the following terms: Reuse, Recycle, Reduce.
29. 3(c)(ii)3 marksDiscuss how the concepts of reuse, recycle and reduce can be applied practically to glass waste.
30. 3(d)5 marksDescribe the chemical processes involved in the production of chlorine and sodium hydroxide when the diaphragm cell is used. Your answer must include the types of reaction taking place and the equations representing the…
31. 3(e)(i)2 marksDescribe the chemical changes which occur to produce hydrochloric acid.
32. 3(e)(ii)1 markDescribe the chemical changes which occur to produce sodium hypochlorite (bleach).
33. 3(e)(iii)2 marksTWO modifications that could be made to the structure of the electrolytic cell to ensure that these chemical changes in (e)(ii) do not occur.