The reaction of V(CO)5(NO) with P(OCH3)3 to give V(CO)4[P(OCH3)3](NO) has the rate law...

The reaction of V(CO)₅(NO) with P(OCH₃)₃ to give V(CO)₄[P(OCH₃)₃](NO) has the rate law

a. Suggest a mechanism for this reaction consistent with the rate law.

b. One possible mechanism consistent with the last term in the rate includes a transition state of formula V(CO)₅[P(OCH₃)₃](NO). Would this necessarily be a 20-electron species? Explain.