Statement A: 50% of a reaction is completed in 50 sec, therefore, 75% of the reaction will be completed in 75 sec,if the order of reaction is zeroStatement B: The rate constant of a zero order reaction depends upon time as k=1t{[A]0−[A]}.

Correct statement 2 is ,Rate constant of any reaction is constant at constant temperature and does not change with time or concentration. However, statement 1 is correct because t=1k{[A]0−[A]}For 50%, t50%=1k[A]0−[A]02=[A]02k=50sec⁡For 75%, t75%=1k[A]0−[A]04                     =[A]0k×34=[A]02k×32=75sec⁡