Question

The standard potential of the electrode Zn²⁺_(0.02M) |Zn_(s) is − 0.76 V. Calculate the electrode potential of the zinc electrode.

Answer 1

Given: C = 0.02, n = 2,

`E_(Zn)^0 = - 0.76 V, E_(Zn) = ?`

`Zn_((aq)(0.02 M))^(2⊕) + 2e^Θ -> Zn_((s))`

`E_(Zn) = E_(Zn)^0 - 0.0592/n log_10  1/([Zn^(2⊕)])`

= `- 0.76 - 0.0592/2 log_10  1/([0.02])`

=  `- 0.76 + 0.0592/2 log_10  [0.02]`

= `- 0.76 + 0.0592/2 xx (- 1. 6990)`

= `- 0. 76 - 0.0503`

∴ E_Zn = − 0.81 V