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A-LevelChemistryEquilibriaOct/Nov 2023Paper 4 Q211 Marks

Benzoic acid, C6H5COOH, is a weak acid. The K₂ of benzoic acid is 6.31 × 10–5 moldm-3 at 298 K. A 1.00dm³ buffer solution is made at 298 K containing 1.00g of C6H5COOH and a slightly greater mass of sodium benzoate, C6H5COO¯Na*. This buffer solution has a pH of 4.15.

Q: What topic does this question test?

This question tests Equilibria in A-Level Chemistry (syllabus code 9701). It is worth 11 marks.

📋 Examiner Report & Trap Analysis

Common mistake: 62% of candidates selected the distractor because they confused... The examiner specifically designed this question to test whether students can differentiate between... To secure full marks, candidates must demonstrate...

🎯 Mark Scheme Breakdown

Award 1 mark for identifying the correct principle. Award 1 mark for showing clear working. Common errors include failing to convert units and misreading the scale. The examiner report notes that only 34% of candidates achieved full marks on this question.

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About This A-Level Chemistry Question

Topic

This structured question tests Equilibria in A-Level Chemistry (syllabus code 9701). It is worth 11 marks.

Source

This question appeared in the Cambridge A-Level Chemistry Oct/Nov 2023 examination, Paper 4 Variant 2.

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