Question

What are two different chemicals that we have added to the carbon cycle that did not previously exist naturally.

i.  Which functional group does each chemical belong to? Explain.

ii. How does the type of bonding and functional group these molecules posses affect their reactivity?

iii.   What are the health and environmental effects of the two chemicals?

Answer 1

Chlorofluorocarbons; CF2Cl2 and

Hydrochlorofluorocarbons: HCF2Cl

i. Halide is the funtional group.

ii. Ffulorine is the most electronegative element and makes the C-l bond partially polar and more reactive.

iii. (a) Exposer to CFCs affects the central nervous system, according to the New Hampshire Department of Environmental Sciences. The result is intoxication similar to alcohol intake and also includes, headaches, tremors and convulsions. Inhalation of CFCs can also disturb heart rhythm, which can lead to death. Exposure to large amount of CFCs could potentially cause asphyxiation, according to the Centers for Disease Control and Prevention.

(b) The ozone (O3) layer in the stratosphere protects life on earth from exposure to dangerous levels of ultraviolet light. It does so by filtering out harmful ultraviolet radiation from the sun. When CFCs and other ozone-degrading chemicals are emitted, they mix with the atmosphere and eventually rise to the stratosphere. There, the chlorine and the bromine they contain catalyze the destruction of ozone. This destruction is occurring at a more rapid rate than ozone can be created through natural processes.

The degradation of the ozone layer leads to higher levels of ultraviolet radiation reaching Earth's surface. This in turn can lead to a greater incidence of skin cancer, cataracts, and impaired immune systems, and is expected also to reduce crop yields, diminish the productivity of the oceans, and possibly to contribute to the decline of amphibious populations that is occurring around the world. (Ref: EPA)