24   9 This question is about the analysis of some organic compounds. (a) A compound A (C3H7Cl) reacts with dilute aqueous sodium hydroxide to produce B (C3H8O). B can be oxidised to C (C3H6O), which cannot be oxidised any further. A reacts with magnesium in dry ether to give D (C3H7MgCl). When carbon dioxide is passed through the solution of D, followed by acidification, E (C4H8O2) is formed. Identify the structures of A to E. (5) 25   (b) An organic compound, Q, contains carbon, hydrogen and nitrogen only. When a 1.19 g sample of the compound was heated with sodium hydroxide solution, all of the nitrogen was converted into ammonia. The ammonia was passed into 100.0 cm3 of 0.225 mol dm–3 hydrochloric acid. NH3(g) + HCl(aq) → NH4Cl(aq) 25.0 cm3 portions of the resulting solution containing unreacted hydrochloric acid required a mean titre of 15.5 cm3 of 0.100 mol dm–3 sodium hydroxide for neutralisation. Calculate the percentage of nitrogen in Q. (5) (Total for Question 9 = 10 marks) TOTAL FOR PAPER = 90 MARKS 26   BLANK PAGE 27   BLANK PAGE 28  