Because of increasing evidence of damage to the ozone layer, chlorofluorocarbon
ID: 805266 • Letter: B
Question
Because of increasing evidence of damage to the ozone layer, chlorofluorocarbon (CFC) production was banned in 1996. However, there are about 100 million auto air conditioners that still use CFC?12 (CF2Cl2).
These air conditioners are recharged from stockpiled supplies of CFC?12.
If each of the 100 million automobiles contains 1.3kg of CFC?12 and leaks 25{ m \%} of its CFC?12 into the atmosphere per year, how much chlorine, in kg, is added to the atmosphere each year due to auto air conditioners? (Assume two significant figures in your calculations.)
Explanation / Answer
Molar mass of CF2Cl2 = 12.01 + 19*2 + 35.45 * 2 = 120.91 g/mol
120.91 g CF2Cl2 contains 35.45 * 2 = 70.9 g chlorine
100 million * 1.1 kg CFC * 23/100 * 70.9 g chlorine/120.91 g CFC
= 15 million kg chlorine
= 1.5 * 10^7 kg/yr