The rate constant for a first order reaction is `7.5 xx 10^(-4) s^(-1)`. If initial concentration of reactant is `0.080 M`, what is the half life of reaction ?

Options

A. `990 s`
B. `79.2s`
C. `12375 s`
D. `10.10 xx 10^(-4) s`

Answer

A

Explanation

Given , `K = 7 xx 0^(-4)s^(-1),[A]_(0) = 0.08 M`
Half life `(t_(1//2))` of a first order reaction is independent of initial concentration and is given as
`t_(1//2) = (0.693)/(k) = (0.693)/(7xx 10^(-4)s) = 990 s`