the formation of no(g) from n2 and o2 has the following proposed mechanism.
N2 (g) + O2 (g) -> 2 NO (g)
step 1 O2 <=> 2O (fast eq)
step 2 O + N2 -> NO + N (slow)
step 3 N + O -> NO (fast)
The experimentally determined rate law for this would be:
1. Rate = kobs (N2)(o2)^1/2
2. Rate = kobs (N2)(O2)
3. Rate = kobs (N2)
4. Rate = kobs (O2)^2
To determine the experimentally determined rate law for a reaction, we need to consider the slowest step in the proposed mechanism. In this case, the slow step is step 2: O + N2 -> NO + N.
The rate-determining step (slow step) is the step that determines the overall rate of the reaction. The reactants involved in this step are N2 and O. According to the balanced equation for this step, the stoichiometric coefficient of N2 is 1, meaning that the concentration of N2 affects the rate of the reaction.
Therefore, the rate law for this reaction would be:
Rate = kobs (N2),
where kobs is the observed rate constant.
Hence, the correct option is:
3. Rate = kobs (N2).