A-LevelChemistryGroup 2Feb/Mar 2021Paper 1 Q151 Mark

An anhydrous white salt, Z, is heated strongly for 30 minutes. A mixture of gases is given off. The solid remaining in the test-tube is then dissolved in a small volume of dilute hydrochloric acid. The addition of a few drops of dilute sulfuric acid to the test-tube causes a white precipitate to form. Which substance could be Z?

Q: What is the correct answer to this A-Level Chemistry question?

The correct answer is B: barium nitrate.

Q: What topic does this question test?

This question tests Group 2 in A-Level Chemistry (syllabus code 9701). It is worth 1 mark.

Abarium carbonate

Bbarium nitrate

Cmagnesium carbonate

Dmagnesium nitrate

✓ Correct Answer

The correct answer is B: barium nitrate

📋 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 multiple-choice question tests Group 2 in A-Level Chemistry (syllabus code 9701). It is worth 1 mark.

Source

This question appeared in the Cambridge A-Level Chemistry Feb/Mar 2021 examination, Paper 1 Variant 2.

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