Answer the question on the basis of passage given below:

For the Transition Elements.

Which transition metal ion $M^{2+}/M$ have standard electrode potential $E°/V = +0.34V$?

Cu

The correct answer is Option (4) → Cu.

The transition metal ion \( \text{M}^{2+}/\text{M} \) with a standard electrode potential \( E^\circ = +0.34 \, \text{V} \) is: Copper (Cu).

The standard electrode potential is a measure of the tendency of a species to gain electrons and be reduced. A more positive \( E^\circ \) value indicates a greater tendency to be reduced.

The standard electrode potentials for the given transition metal ions are:

Copper (Cu): \( \text{Cu}^{2+} + 2\text{e}^- \rightarrow \text{Cu} \) has a standard electrode potential \( E^\circ = +0.34 \, \text{V} \).

Cobalt (Co): \( \text{Co}^{2+} + 2\text{e}^- \rightarrow \text{Co} \) has a lower standard electrode potential (around \( E^\circ \approx +0.28 \, \text{V} \)).

Zinc (Zn): \( \text{Zn}^{2+} + 2\text{e}^- \rightarrow \text{Zn} \) has a standard electrode potential of \( E^\circ = -0.76 \, \text{V} \), indicating it is a good reducing agent.

Manganese (Mn): The standard electrode potential for \( \text{Mn}^{2+} + 2\text{e}^- \rightarrow \text{Mn} \) is approximately \( E^\circ \approx -1.18 \, \text{V} \).

Thus, the correct answer is Copper (Cu), which has the standard electrode potential of \( +0.34 \, \text{V} \).