The half-life for a zero order reaction

The half-life is proportional to the concentration, and so the larger the concentration the greater is the half-life. The half-life decreases as the reaction proceeds. 

Question. Show that the following reaction obeys zero order kinetics, and find the rate constant and first half-life. 

The following problem illustrates the use which can be made of half-lives. 

Question. Look at the answer to problem 3.7 and infer the order of each reaction. Answer. 

Reaction A half-life increases as concentration decreases, second order. 

---