Define the following terms :
(i) Half- life of a reaction `(t_(1//2))`
(ii) Rate constant `(k)`.

Explanation

(i) Half life period `(t_(1//2))` is the time in which half of the substance has reacted . `t_(1//2)=[A]_(0)/(2k)`
(ii) Rate constant : It is the rate of reaction when the molar concentration of each reactant is taken as unity.