Assertion: `50%` of reaction is completed in `50 sec`, therefore, `75%` of the reaction will be completed in `75 sec`.
Reason: The rate constant of a zero order reaction depends uopn time as `k = (1)/(t){[A]_(0) - [A]}`.

Options

A. Statement-1 is True, Statement-2 is True , Statement-1 is a correct explanation of Statement-1.
B. Statement-1 is True, Statement-2 is True , Statement-2 is NOT the correct explanation of Statement-1.
C. Statement-1 is True, Statement-2 is False.
D. Statement-1 is False, Statement-2 is True.

Answer

C

Explanation

Correct Statement-2. 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=(1)/(k){[A]_(0)-[A]}`
For `50%,t_(50%)=(1)/(k){[A]_(0)-([A]_(0))/(2)}=([A]_(0))/(2k)=50" sec"`
For `75%,t_(75%)=(1)/(k){[A]_(0)-([A]_(0))/(4)}`
`=([A]_(0))/(k)xx(3)/(4)=([A]_(0))/(2k)xx(3)/(2)=75" sec"`