Chemistry · Oct / Nov 2018 · Paper 11 · Question 20

Three separate mixtures of a solution and a solid are made, as shown in the table. The mixtures are warmed. In which mixtures does gas form? | | NaOH(aq) and NH4Cl(s) | H2SO4(aq) and NH4Cl(s) | H2SO4(aq) and Mg(s) | |---|---|---|---| | A | ✓ | ✓ | ✗ | | B | ✓ | ✗ | ✓ | | C | ✗ | ✓ | ✗ | | D | ✗ | ✗ | ✓ | key ✓ = gas forms ✗ = no gas forms

1. A✓ ✓ ✗
2. B✓ ✗ ✓
3. C✗ ✓ ✗
4. D✗ ✗ ✓

As printed in the paper