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1 markAcidic and Basic Character of Organic Compounds

CAPE Chemistry Unit 2 · May/June 2022 · Paper 2 · Question 1(b)(ii)

Chloroethanoic acid dissociates in water according to the equation: CH₂ClCOOH + H₂O → CH₂ClCOO⁻ + H₃O⁺.

Write an expression to show how pKₐ is derived from Kₐ.

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Other parts of this question

  1. 1(a)(i)State the reagents and conditions for reaction I (from A to B).[2 marks]
  2. 1(a)(ii)State the reagents and conditions for reaction II (from A to C).[2 marks]
  3. 1(a)(iii)Draw the displayed structures and provide names for EACH of the following compounds: Compound D, Compound E.[4 marks]
  4. 1(b)(i)Write an expression for the Kₐ of chloroethanoic acid.[2 marks]
  5. 1(c)(i)Complete 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.[4 marks]
  6. 1(c)(ii)Give reasons for your assignments in (c)(i).[5 marks]
  7. 1(d)Account for the fact that the pKₐ of phenylamine is greater than that of ethylamine.[4 marks]
  8. 1(e)(i)Draw the structure of the monomer used to form polymer P and name the type of polymerization involved.[2 marks]
  9. 1(e)(ii)Draw the structures of the two compounds which react to form the polymer Q and name the type of polymerization involved.[3 marks]
  10. 1(e)(iii)Identify a compound which in aqueous solution will break down polymer Q but not polymer P.[1 mark]

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