Test for carbon dioxide by burning a splint, using litmus or indicator papers or running the gas through lime water. Additionally, according to the National Institutes of Health, a blood test can be performed to determine the amount of carbon dioxide in a person's blood.
A chemistry lab offers several different ways in which a person can test a gas to determine if it is carbon dioxide, or CO2:
Light a splint
- Use litmus paper
- Use universal indicator paper
- Run the gas through lime water
Collect carbon dioxide gas in a tube by downward delivery or using a gas syringe. Light a splint, which is a long, thin strip of wood. Insert the lit splint into the tube with the gas. If carbon dioxide is in the tube, the flame will go out.
Place a piece of moist litmus paper into the tube with the carbon dioxide gas. If the gas is present, the litmus paper will turn from blue to red.
Place a piece of moist universal indicator paper into the gas tube. If carbon dioxide gas is present, the universal indicator paper will turn yellow.
When carbon dioxide is run through lime water, the water turns cloudy. This is because the water is a solution of calcium hydroxide, and when it reacts with carbon dioxide, a solid precipitate of calcium carbonate forms.