A-LevelChemistryAnalytical techniques9701/41 · May/June 2021 · Q96 Marks

The carbon-13 (¹³C) NMR spectrum of compound A, C₈H₈O₂, contains six peaks. Compound A reacts with an excess of bromine water to give compound B, C₈H₆Br₂O₂. Compound A reacts with alkaline aqueous iodine to form a yellow precipitate C and compound D. Compound D reacts with PCl₅ to form compound E, C₇H₅O₂Cl. Compound E reacts with propan-2-ol to form compound F. Draw the structures of compounds A, B, C, D, E and F in the boxes.

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Mark scheme

Marking points from the official mark scheme (May/June 2021). The mark or mark type is shown in brackets.

[1] A: [Figure showing 1-(4-hydroxyphenyl)ethan-1-one: benzene ring with -OH para to -COCH3]
[1] B: [Figure showing 1-(3,5-dibromo-4-hydroxyphenyl)ethan-1-one: benzene ring with -OH para to -COCH3, and Br at 3 and 5 positions]
[1] C: [Figure showing CHI3]
[1] D: [Figure showing 4-hydroxybenzoic acid: benzene ring with -OH para to -COOH]
[1] E: [Figure showing 4-hydroxybenzoyl chloride: benzene ring with -OH para to -COCl]
[1] F: [Figure showing isopropyl 4-hydroxybenzoate: benzene ring with -OH para to -COO-CH(CH3)2]

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