Question

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

Answer 1

Correct Answer - B
For the first order reaction,
Rate =K[A]
Given that,
`(dx)/(dt)=1..5xx10^(-2)"mol L^(-1)min"^(-1)`
`K=? and [A]=0.5 M`
`therefore " "1.5xx10^(-2)=Kxx0.5`
`therefore" "K=(1.5xx10^(-2))/(0.5)=3xx10^(-2) "min"^(-1)`
"For first order reaction"
Half-life,period `t_(t//2)=(0.693)/(K)=(0.693)/(3xx10^(-2))=23.1"min`