Chlorofluorocarbons (CFC) act as catalysts for the destructionof ozone in the up
ID: 678823 • Letter: C
Question
Chlorofluorocarbons (CFC) act as catalysts for the destructionof ozone in the uper atmosphere. Ultra violet light from the sunbreaks carbon-chlorine bonds in CFC's.
CF2Cl2 CF2Cl + Cl
The Cl atom reacts with ozone.
Cl + O3 ClO + O2
ClO + O Cl + O2
The direct reaction is
O3 + O 2 O2
Which of the following are true about thesereactions ? More than onecan be correct
a) The direct reaction breaks down O3 at a fasterrate than the same reaction where Cl is used as a catalyst.
b) While Cl can be used as a catalyst, it will not appear as anintermediate in the resulting two-step mechanism since it isregenerated in the last step.
c) The presence of Cl provides a mechanism with lowerEa 's than the direct reaction (in the absence ofCl)
d) E (reaction energy) is the same whether Cl is presentas a catalyst or not
e) When Cl is used as a catalyst it is a homogeneouscatalyst