The rate law for the reaction a → products is rate = 4.36 × 10-2 m-1s-1 [a]2. what is the half-life of the reaction if the initial concentration of a is 0.250 m?

The formula for the half life is simply:

t1/2 = ln 2 / k

where k is the rate constant and can be calculated from the formula:

rate = k [A]

where [A] is the initial concn = 0.25 M

k = 4.36 × 10-2 M s-1 / 0.25 M = 0.1744 s-1

t1/2 = ln 2 / 0.1744 s-1

t1/2 = 3.97 s