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3 marksAcidic and Basic Character of Organic Compounds

CAPE Chemistry Unit 2 · May/June 2024 · Paper 2 · Question 1(c)(v)

Figure 1 shows a reaction sequence of an isomer of Hydrocarbon A. The scheme depicts the reaction of A with Cl₂, hv to form B, and B reacting with Reagent X to form Compound C (2,3-dimethylbutan-2,3-diol).

Given that ethanol has a pKa of 16, suggest whether the pKa of Compound C is higher or lower than that of ethanol. Give a reason for your suggestion.

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Other parts of this question

  1. 1(a)(i)Define the term 'structural isomerism'.[2 marks]
  2. 1(a)(ii)List THREE types of structural isomerism.[3 marks]
  3. 1(a)(iii)Define ONE of the types of structural isomerism listed in (a) (ii).[2 marks]
  4. 1(b)(i)Draw TWO isomers that have ONE methyl substituent.[2 marks]
  5. 1(b)(ii)Draw THREE isomers that contain ONLY secondary and tertiary carbon atoms and at least TWO methyl substituents.[3 marks]
  6. 1(c)(i)Give the structural formula of Compound A, Compound B and Reagent X.[5 marks]
  7. 1(c)(ii)List the names of the steps involved in going from A to B in Figure 1.[3 marks]
  8. 1(c)(iii)Using curved arrows, give the mechanism for the first step listed in (c) (ii) on page 6.[2 marks]
  9. 1(c)(iv)Give the structural formula of a product that can be formed alternatively to Compound B in (c) (i).[1 mark]
  10. 1(c)(vi)If the reaction of going from A to B was performed in a closed vessel, what would be the expected colour change?[2 marks]
  11. 1(c)(vii)In an experiment, two drops of universal indicator were added to 1 cm³ of ethanol in Test tube 1 and 1 cm³ of Compound C in Test tube 2. Suggest the colours…[2 marks]

More practice: the rest of this paper · more Acidic and Basic Character of Organic Compounds questions · all CAPE Chemistry Unit 2 past papers