paper-2

1. Which acid and base react together to produce an insoluble salt?

A hydrochloric acid and sodium hydroxide   B nitric acid and calcium oxide

C sulfuric acid and barium hydroxide D sulfuric acid and zinc oxide

2. Which calcium compound does not increase the pH of acidic soils?

A calcium carbonate   B calcium hydroxide

C calcium oxide D calcium sulfate

3. The diagrams show an experiment with aqueous ammonium chloride.

A gas, Y, is produced and the litmus paper changes colour.

What are solution X and gas Y?