Question

When metal oxides or metal hydroxides react with acid, they form salt and X. What is X?

• A. Hydrogen
• B. Water
• C. Carbon Dioxide
• D. Oxygen

Answer 1

The correct option is B Water

When metal oxides or metal hydroxides react with acid, they form salt and water.
For example:
Zinc oxide reacts with hydrochloric acid to give zinc chloride and water. The reaction takes place as follows:

$\text{ZnO}\text{(aq)}+2\text{HCl}\text{(aq)}\to {\text{ZnCl}}_2\text{(aq)}+{\text{H}}_2\text{O}\text{(l)}$