It is colorless and odorless, and it has a freezing point of -55.6 degrees Celsius. Carbon dioxide is soluble in water, acetone and ethanol. It is an atmospheric gas that is produced by both combustion and respiration.
Carbon dioxide is a linear covalent molecule as well as an acidic oxide, which reacts to water to form carbonic acid. Carbon dioxide is widely used in many industrial processes that require large scale refrigeration, particularly the freezing and chilling of foods. Carbon dioxide is vital to the survival of plant life and is produced as a waste product by both humans and animals during the process of cellular respiration.
Carbon dioxide is heavier than air and can accumulate in environments that lack suitable ventilation. The gas can pose an asphyxiation hazard to those who are working with it in large quantities. Frozen carbon dioxide evaporates at room temperature without passing through a liquid phase and is known as dry ice in its solid form. Carbon dioxide is a waste gas that is produced by the combustion of fossil fuels. Atmospheric carbon dioxide is a greenhouse gas that serves to trap heat from the planet's surface that would otherwise radiate back into space.