An organic chemist uses analytical chemistry

Organic chemistry is the study of chemicals that do not contain carbon. ... An organic chemist uses analytical chemistry. 17. Applied chemistry is used to attain specific goals.

Half life =  1.540 s

Explanation:

A → 3B+2C

Initial concentration = 0.535 mol L−1

rate constant k = 0.450 s-1

half life t1/2 = ?

Since the reaction s a first order reaction

Half life is given by;

t1/2 = 0.693 / k

t1/2 = 0.693 / 0.450 = 1.540 s