In an electrolytic cell one litre of 1M aqueous solution of `MnO_(4)^(-)` is reduced to `MnO_(4)^(-2)` at cathode. How many faradays would be required so that the solution becomes `0.899` M `MnO_(4)^(-)`

Options

A. 10 Faradays
B. `0.1` Faradays
C. `1.0 xx 10^(-4) " Faraday"`
D. `1 xx 10^(-2) " Faraday"`

Answer

B

Explanation

No. of moles of `MnO_(4)^(-)` changed to
`MnO_(4)^(-2)=1-0.899=0.101`
For 1 mole =1F, For `0.0101` mole `=0.1` F