In a first order reaction, the concentration of the reactants is reduced to `25%` in one hour. The half-life period of the reactions is

Options

A. 2 hrs
B. 2hrs
C. `1//2` hrs
D. `1//4` hrs

Answer

C

Explanation

`k=(2.030)/(t)log.((a)/(a-x))`
`k=(2.303)/(1) log. ((100)/(5))=2xx0.693`
`t_(1//2)=(0.693)/(k)=(0.693)/(2xx0.693)=(1)/(2)hr`