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)/(40 min)"log"(0.1)/(0.025)`
`=(2.303)/(40min)log 4`
`=(2.303xx0.6021)/(40)"min"^(-1)`
Rate `=k[X]`
`=(2.303xx0.6021)/(40)xx10^(-2) "M min"^(-1)`
`= (2.303xx6.021)/(4)xx10^(-4)"M min"^(-1)`
`=3.47 xx10^(-4)"M min"^(-1)`.