The magnitude `(` but not the sign `)` of the standard reduction potentials of two metals `X` and `Y` are `:`
`Y^(2)+2e^(-) rarr Y |E_(1)^(c-)|=0.34V`
`X^(2)+2e^(-) rarr X |E_(2)^(c-)|=0.25V`
When the two half cells of `X` and `Y `are connected to construct a cell, eletrons flow from `X` to `Y`. When `X` is connected to a standard hydrogen electrode `(SHE)`,electrons flow from `X` to `SHE`.
If a half call `X|X^(2)(0.1M)` is connected to another half cell `Y|Y^(2+)(1.0M)` by means of a salt bridge and an external circuit at `25^(@)C`, the cell voltage would be

Options

A. `0.06V`
B. `0.12V`
C. `0.62V`
D. `0.72V`

Answer

C

Explanation

When connected, electron flow from `X` to `Y` means,
`E_(Y^(2+)//Y)^(@) gt E_(X^(2+)//X)^(@)`
and when `X` is connected to `SHF`, e flow from `X` to `SHE` means.
`E_(X^(2+)//X)^(@)`
Cell reaction,
`X |X^(2+)(0.1M) ||Y^(2+)(1.0M)|Y`
`E_(cell)^(@) = 0.34 +0.25 = 0.59V`
`E_(cell) = E_(cell)^(@)-(0.06)/(n)log.([X^(2+)])/([Y^(2+)]) = 0.59 -(0.06)/(2)log.(0.1)/(1) =0.59 +0.03`
`E_(cell) = 0.62V`