Respiration by living organisms can be investigated by carrying out experiments to show the production of carbon dioxide and heat.
Investigating carbon dioxide production
Limewater turns milky in the presence of carbon dioxide. It can be used to show that exhaled air contains more carbon dioxide than inhaled air.
Carbon dioxide dissolves in water to form a weakly acidic solution. Hydrogencarbonate indicator is used to show the presence of carbon dioxide in solution. It is:
