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4 marksStructure and Formulae

CAPE Chemistry Unit 2 · May/June 2026 · Paper 2 · Question 1(b)(ii)

Compound A contains carbon, hydrogen and oxygen. Combustion analysis of 0.544 g of Compound A gave 1.039 g of CO2 and 0.637 g of H2O.

Calculate the empirical formula of Compound A.

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Other parts of this question

  1. 1(a)(i)Describe the term 'homologous series'.[2 marks]
  2. 1(a)(ii)State the name of a homologous series which only contains aliphatic hydrocarbons.[1 mark]
  3. 1(a)(iii)Draw the displayed structural formula of a three-carbon compound of the named homologous series in (a) (ii).[1 mark]
  4. 1(a)(iv)Write the IUPAC name of the displayed structural formula in (a) (iii).[1 mark]
  5. 1(b)(i)Distinguish between empirical formula and molecular formula.[2 marks]
  6. 1(b)(iii)If the molecular mass of Compound A is 46 a.m.u, what is the molecular formula?[1 mark]
  7. 1(c)(i)State the name of the reagent C.[1 mark]
  8. 1(c)(ii)State the name of the primary amine, B.[1 mark]
  9. 1(c)(iii)Draw the displayed structural formula of primary amine, B.[1 mark]
  10. 1(c)(iv)State the characteristic physical property of primary amine, B which can be observed.[1 mark]
  11. 1(c)(v)State the colour changes which would be observed if litmus is added to a solution of primary amine, B.[2 marks]
  12. 1(d)Using pKa values of 16, 4.8 and 0.6, complete Table 1 with the correct pKa value for EACH organic compound.[3 marks]
  13. 1(e)(i)State the characteristic physical property of the ethyl ethanoate.[1 mark]
  14. 1(e)(ii)State TWO differences between acid hydrolysis and alkaline hydrolysis of ethyl ethanoate.[2 marks]
  15. 1(e)(iii)Write balanced chemical equations for EACH of the following. Acid hydrolysis of ethyl ethanoate. Alkaline hydrolysis of ethyl ethanoate.[4 marks]
  16. 1(e)(iv)Outline how biodiesel (for diesel engines) is made by the process of transesterification.[2 marks]

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