A second-order reaction of the type A + 2 B --7 P was carried out in a

Question:

A second-order reaction of the type A + 2 B --7 P was carried out in a solution that was initially 0.075 mol dm3 in A and 0.030 mol dm3 in B. After 1.0 h the concentration of A had fallen to 0.045 mol dm-1,
(a) Calculate the rate constant.
(b) What is the half-life of the reactants?