Carbon Dioxide Essay

Carbon dioxide is a colorless gas, it has a small but sharp odor and a slightly sour taste. Each molecule of carbon dioxide consists of one atom of carbon and two atoms of oxygen. Its chemical formula is CO2. Carbon Dioxide is about 1.5 times heavier than air. The specific volume at atmospheric pressure (101.3 kilopascals) and 70º F (21º C) is 8.74 ft3/lb. Under normal conditions it remains stable, inert and non-toxic. To liquefy CO2 it must be under 300 pound per inch gage(psig) at 0º F or 838 psig at 70º F. Above the critical temperature of 87.9º F, at which all three phases gas, liquid, or solid may exist in equilibrium with one another, CO2 can exist only as a gas, no matter what amount of pressure. When liquid CO2 is cooled to -69.9º F and the pressure drops to 60.4 psig it turns into dry ice snow. All CO2 existing in the atmosphere is estimated to be 720 x 109. Carbon dioxide makes up about 0.03 percent of the air. Although that is a small amount, plants and animals depend upon it for life. Green plants make their nutrients with it. They mix the carbon dioxide with water to make sugar by a process called photosynthesis. From the sugar,

CO2 can be transported three ways: in high pressure uninsulated steel cylinders, as a low-pressure liquid in insulated truck trailers or rail tank cars, and as dry ice. The size of the high-pressure cylinders is limited because of the weight involved. Most commercial cylinders contain either twenty or fifty pounds of CO2. Laws that govern the vehicle weight restrict truck trailers capacity. Right now about twenty tons of liquid CO2 may be shipped on an insulated trailer. Carbon dioxide gas dissolves in water, forming carbonic acid. When this weak acid reacts with some substances, it forms products called carbonates. One carbonate of importance is sodium bicarbonate, also known as baking