O-LevelChemistryAcids, Bases & Salts5070/11 · Oct/Nov 2016 · Q21 Mark

Two experiments were carried out. In experiment 1, ammonium carbonate was reacted with dilute hydrochloric acid. In experiment 2, ammonium carbonate was heated with aqueous sodium hydroxide. In each experiment, the gas evolved was tested with damp blue litmus paper and damp red litmus paper. Which row correctly shows the colour of both the pieces of litmus paper at the end of each experiment?

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Aexperiment 1: blue, experiment 2: blue

Bexperiment 1: blue, experiment 2: red

Cexperiment 1: red, experiment 2: blue

Dexperiment 1: red, experiment 2: red

✓ Correct answer

C: experiment 1: red, experiment 2: blue

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Topic: Acids, Bases & Salts, O-Level Chemistry (syllabus 5070). Multiple choice, 1 mark.
Source: O-Level Chemistry, Oct/Nov 2016 Paper 1 Variant 1, question 2.

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