Question

Which of the following is the cathodic half cell reaction of the given galvanic cell?

• A. $Cu\left(s\right)\to C{u}^{2+}\left(aq\right)+2e^{-}$
• B. $Ag\left(s\right)\to A{g}^{2+}\left(aq\right)+e^{-}$
• C. $2A{g}^{+}\left(aq\right)+2e^{-}\to 2Ag\left(s\right)$
• D. $C{u}^{2+}\left(aq\right)+2e^{-}\to Cu\left(s\right)$

Answer 1

The correct option is C $2A{g}^{+}\left(aq\right)+2e^{-}\to 2Ag\left(s\right)$

In the given galvanic cell, the electrons flows copper rod to the silver rod.
Thus, the oxidation reaction occurs at the copper rod and it act as the anode.
The reduction reaction occurs at the silver rod and it act as cathode.
Thus, the anode half cell is $Cu$ in its aqueous salt solution and cathode half cell is $Ag$ in its aqueous salt solution.
Hence, the half cell reactions are
At anode : $Cu\left(s\right)\to C{u}^{2+}\left(aq\right)+2e^{-}$
At cathode : $2A{g}^{+}\left(aq\right)+2e^{-}\to 2Ag\left(s\right)$
Thus, option (c) is correct.