Answer:
The correct answer is - acid.
Step-by-step explanation:
The presence of carbonate in a solid or aqueous solution can be detected with the help of a chemical. This chemical is acid which is added to the compound or solution in a dilute form that leads to the formation of the bubbles of the carbon dioxide gas.
Carbonate ions react with the acid and form carbon dioxide gas that can be confirmed by Limewater. Thus, the correct answer is - acid.