How can you identify carbon dioxide in a reaction?

Carbon dioxide can be identified in a reaction by using limewater, a dilute solution of calcium hydroxide. When carbon dioxide is bubbled through limewater, it reacts to form calcium carbonate, which causes the solution to turn cloudy. Additionally, you can use a pH indicator; carbon dioxide lowers the pH of a solution, indicating its presence. These methods provide simple yet effective means of detecting carbon dioxide in chemical reactions.