The direct current of `1.25A` was passed through `200mL` of `0.25M Fe_(@)(SO_(4))_(3)` solution for a period of 1.1 hour. The resulting solution in cathode chamber was analyzed by titrating against `KMnO_(4)` solution 25Ml permaganate solution was required to reach the end point. Determine molarity of `KMnO_(4)` solution.

Answer

`0.41M`

Explanation

For `Fe^(+3) +e^(-) rarr Fe^(+2) E^(@) = 0.77`
so `Fe^(+3)` will reduce to `Fe^(+3)`
`(Fe^(+3), Fe^(+3))`
Faraday of current passed
`=(1.25 xx 1.1 xx 3600)/(96500) = 0.0513`
meq.of `Fe^(+2) =` meq of `KMnO_(4)` required `=51.3`
`(Fe^(+2) = KmnO_(4) =51.3)`
`51.3 = M xx 5 xx 25`
`M = 0.41`