NaOH(aq) is added to NH4Cl(aq). The mixture is warmed. The gas that is produced turns damp red litmus paper blue. Which row is correct?
✓ Correct Answer
The correct answer is B: behaviour of the ammonium ion in NH4Cl: Brønsted-Lowry acid; behaviour of the water present on the litmus paper: Brønsted-Lowry acid
📋 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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