Normal aluminimum electrode cupled with normal hydrogen electrode gives an emf of ` 1.66 V`. So the standard electrode potential of aluminimu is ,

Options

A. `-1.66 V`
B. `+1.66 V`
C. `-0.83 V`
D. `+0.83 V`

Answer

A

Explanation

`E_("cell")^(@) = 1.66 = E_(H^(+)//H_(2))^(@) - E_(Al^(3+)//Al)^(@)`
`= O - E_(Al^(3+)//Al)^(@)` or `E_(Al^(3+)//Al)^(@) = -1.66 V`