Question

For the given cell, $Mg|M{g}^{2+}||C{u}^{2+}|Cu$

• A. $Cu$ is an oxidising agent
• B. $Cu$ is cathode
• C. $Mg$ is cathode.
• D. The cell reaction is $Mg+C{u}^{2+}\to M{g}^{2+}+Cu$

Answer 1

Answer: (B), (D)

The cell reaction is $Mg+C{u}^{2+}\to M{g}^{2+}+Cu$

Understanding the given cell

$Mg|M{g}^{2+}||C{u}^{2+}|Cu$

where,

i) $Mg|M{g}^{2+}\to$ Represents the oxidation of $Mg$ at anode.

ii) $C{u}^{2+}|Cu\to$ Represents the reduction of $Cu$ at cathode.

iii) $|\to$ It is used to separate species in different phase.

iv) $||\to$ Denotes salt bridge between two half cells.

Understanding corresponding cell reactions

$Mg|M{g}^{2+}||C{u}^{2+}|Cu$

Corresponding half-cell reactions are,

At cathode: $C{u}^{2+}\left(aq\right)+2e^{-}\to Cu\left(s\right)$

At anode: $Mg\left(s\right)\to M{g}^{2+}\left(aq\right)+2e^{-}$

Overall reaction:

$Mg\left(s\right)+C{u}^{2+}\left(aq\right)\to Cu\left(s\right)+M{g}^{2+}\left(aq\right)$

Therefore, $Mg$ is anode while $Cu$ is cathode.

Since, $C{u}^{2+}$ is getting reduced to $Cu$ and $Mg$ is getting oxidized to $M{g}^{2+}$, this signifies that $C{u}^{2+}$ acts as an oxidizing agent by itself getting reduced and oxidising $M{g}^{2+}$. \

Hence, the correct options are (b) and (c).