When the initial concentration of a zero order reaction is doubled, the half-life of the reaction is:

Step-by-step solution

For a zero order reaction, the half-life is given by the expression: t_ 1/2 = [A]₀ 2k where [A]₀ is the initial concentration and k is the rate constant. This shows that the half-life is directly proportional to the initial concentration ( t_ 1/2 [A]₀ ). Therefore, when the initial concentration is doubled, the half-life of the reaction is also doubled. Answer: doubled