A follows first order reaction.
`(A) rarr Product`
The concentration of `A` changes form `0.1 M` to `0.025 M` in `40 min`. Find the rate of reaction of `A` when the concentration of `A` is `0.01 M`.

Options

A. `1.73 xx 10^(-4) "M/min"`
B. `3.47 xx 10^(-5) "M/min"`
C. `3.47 xx 10^(-4) "M/min"`
D. `1.73 xx 10^(-5) "M/min"`

Answer

C

Explanation

`k=(2.303)/(t)"log"(Ct)/(Ct)=(2.303)/(40 min)"log"(0.1M)/(0.025)`
`=(2.303)/(40)log 4=(2.303xx0.6021)/(40)"min"^(-1)`
Rate `=K[A]=(2.303xx0.6021)/(40)"min"^(-1)xx0.01M`
`=3.47xx10^(-4)minxx0.01M`
`=3.47 xx 10^(-4)M//min` .