To identify the presence of carbon dioxide gas in a sample, you can perform a simple experiment using limewater. Here’s what you’ll need to do:
1. Prepare two test tubes, one containing the sample gas and the other containing limewater.
2. Bubble the gas sample into the limewater solution.
3. Observe the limewater solution. If the limewater turns cloudy, this indicates that the sample gas contains carbon dioxide.
The limewater turns cloudy because the carbon dioxide and calcium hydroxide react to form calcium carbonate. Calcium carbonate is an insoluble white precipitate, so all the little particles make the solution appear cloudy.