`Al(OH)_(3)` का `K_(sp) = 10 ^(-36)`
और `E _(Al ^(3+) //Al) ^(@) = - 1. 66 V`
और 298 K पर`Al ^(3+) //Al` युग्म का अपचयन विभव है

Options

A. `1.07 V`
B. `2.25 V`
C. `-1.07 V`
D. `-2.25 V`

Answer

D

Explanation

`Al ^(3+) + 3e ^(-) to Al`
`E = E ^(@) - (0.056)/(3) log "" (1)/([Al ^(3+)])`
`pH = 12 implies pOH = 14-12 =2`
`implies [OH ^(-)] =0.01 M`
`[Al ^(+3)] = (10 ^(- 38))/( [ OH ^(-)] ^(3)) = (10 ^(-38))/( (0.01) ^(3)) = 10 ^(-30)`
`therefore E = - 1. 66 - (0.059)/(3) log ((1)/( 10 ^(-30)))`
`=- 1. 66 - (0.059)/(3) xx 30 = - 1. 66 - 0.59 =- 2. 25 V`