The rate of first-order reaction is `1.5 xx 10^(-2) M "min"^(-1)` at `0.5 M` concentration of reactant. The half-life of reaction is

Options

A. 7.53 min
B. 0.383 min
C. 23.1 min
D. 8.73 min

Answer

C

Explanation

For a first order reaction
Rate = k (conc.)
`:. k=("Rate")/(("conc."))=(1.5xx10^(-2)"mol L"^(-1)"min"^(-1))/("0.5 mol L"^(-1))`
`=3xx10^(-2)"min"^(-1)`
`t_(1//2)=(0.693)/(k)=(0.693)/(3xx10^(-2))min`
`=(69.3)/(3)min=23.1 min`.