Standard electrode potential for `Sn^(4+)//Sn^(2+)` couple is `+ 0.15 V` and that for the `Cr^(3+) //Cr ` coule is `-0. 74 V`. These two coules in their standard state are connected to made a cell. The cell potential wil be .

Options

A. ` + 1.83 V`
B. ` + 1.19 V`
C. ` + 0. 18 V`
D. ` + 0.89 V`

Answer

D

Explanation

`Sn^(4+) = 2e rarr Sn^(2+) , E_3^2 = 0. 325 V`
` Cr^(3+) + 3 e rarr Cr, E_(RP)^@ =- 0. 74 V` (Higher `E_(OP`)
Redox change `2 Cr + 3 Sn^(4+) rarr 2 Cr^(3+) + 3 Sn^(2+)`
` :. E_(cell) = E_(POCr)^2 = E_(RP)^@ = 0.15 = + 0. 89 V`.