[the_negro_puppy]

Hi, as part of revision for my exam tomorrow, i have two questiosn that i cannot find the answers to:

1) How does sulfur dioxide get oxidised in the troposphere at night when hydroxyl radical concentration falls to a minimum?

2) Why os the abstraction of an H atom by O* ( an exicited atomic oxygen) is faster than H abstraction by O (atomic oxygen)? Explain your answer by drawing a potential energy profiel for each reaction.

Thanks very much for any help.