Shown below is a proposed mechanism for the overall reaction between HBr and oxygen. Which statement regarding the mechanism is correct?

Question

1. the rate-determining step is step 2
2. H₂O(g) is a reaction intermediate
3. step 1 is bimolecular
4. the rate law for the overall reaction is r = k[HBr]⁴[O₂]
5. the reaction will go faster if [Br₂] is increased

Answer 1

1. the rate-determining step is step 2 - False. Rate determining step is step 1
2. H₂O(g) is a reaction intermediate - False. H2O is a product, not an intermediate
3. step 1 is bimolecular - True. It involves interaction of 2 molecules, HBr and O₂
4. the rate law for the overall reaction is r = k[HBr]⁴[O₂] - False. rate = k[HBr][O₂]
5. the reaction will go faster if [Br₂] is increased - False. Increasing [Br₂] will reverse the reaction