Question

4. Give a standard test of carbon dioxide gas. Write an equation to support your answer. Is it a physical or a chemical change? plz help me out I don't understand the question any way

Answer 1

Explanation:

Lets talk about the case when carbon dioxide is allowed to pass through $Ca(OH)_{2}$ (lime water).

When $CO_{2}$ is passed through lime water, lime water turns milky. This is due to the formation of $CaCO_{3}$  ,Calcium carbonate which appears as a white precipitate.

$Ca(OH)_{2} + CO_{2} = CaCO_{3} + H_{2}O$