The newest 8 of 8 written questions, plus 1 multiple-choice. Open one to see it on the real paper.
Identify compound V.
See it on the paper →Ethanedioyl chloride, (COCl ) 2 , can be prepared by reacting ethanedioic acid, (COOH) 2 , with an excess of SOCl 2 . Write an equation for this reaction.
See it on the paper →Benzoyl chloride, C 6 H 5 COCl, can be synthesised by the reaction of benzoic acid with either PCl 5 or SOCl 2 . Complete the equations for these reactions. reaction 1 C 6 H 5 COOH + PCl 5 → C 6 H 5 COCl + + reaction 2 C 6 H 5 COOH + SOCl 2 → C 6 H 5 COCl + +
See it on the paper →Use your answer to (c)(i) to suggest why it is easier to isolate, in a pure form, the C 6 H 5 COCl from reaction 2 compared to reaction 1.
See it on the paper →Complete the diagram to show the mechanism for the reaction between C 6 H 5 COCl and H 2 O. Include charges, dipoles, lone pairs of electrons and curly arrows as appropriate. O C products Cl H 2 O
See it on the paper →Name the type of mechanism you showed in (d)(i).
See it on the paper →Compound A contains chlorine. Give the structural formula and name of A. structural formula name
See it on the paper →State a suitable reagent benzene‑1,4‑dicarboxylic acid. to produce benzene‑1,4‑dioyl chloride from
See it on the paper →Many candidates could see the significance of the SO2 and HCl being gaseous. Some incorrectly referenced aqueous conditions. The synthesis of benzoyl chloride would not work with water present.
— Examiner report, May/June 2022, 9701/43 Q5(c)(ii) (Cambridge)
This question set a difficult and very precise task to the candidates. Most candidates were able to make a start on the mechanism and some were able to reproduce all of it to a high standard. The task required very careful drawing of the curly arrows involved. Single headed arrows, which show the movement of single electrons, are inappropriate for the description of this mechanism and did not gain...
— Examiner report, May/June 2022, 9701/43 Q5(d)(i) (Cambridge)
The structural formula was well known but the name was less well known. Incorrect names such as ethyl chloride and chloroethanoic acid were seen.
— Examiner report, October/November 2020, 9701/42 Q6(c)(i) (Cambridge)
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