How could you test carbon dioxide in combustion?

To test for carbon dioxide (CO2) in combustion, you can use a simple method involving limewater, which is a saturated solution of calcium hydroxide. When CO2 is bubbled through limewater, it reacts to form calcium carbonate, resulting in a milky precipitation. This change in appearance indicates the presence of CO2. Additionally, using a gas sensor specifically designed to detect CO2 can provide a more quantitative measurement.