From the following, identify the reaction having the top position in the EMF series (standard reduction potential) according to their electrode potential at 298 K.
| 1. | Mg2++ 2e– → Mg(s) | 2. | Fe2+ + 2e– → Fe(s) |
| 3. | Au3++ 3e– → Au(s) | 4. | K++ 1e – → K(s) |
Standard electrode potentials are:
\(F e^{+ 2} / F e\) , \(E^\circ\) \(=\) \(- 0 .44\)
\(F e^{+ 3} / F e^{+ 2}\), \(E ^\circ\) \(= 0 . 77\)
Choose the correct observation when \(𝐹𝑒^{+2}\) , \(𝐹𝑒^{+3}\) and \(Fe_{(solid)}\) are kept together:
1. increases
2. decreases
3. remains unchanged
4. decreases