Question

In the Daniel cell, $Zn\left|Z{n}^{2+}\Vert C{u}^{2+}\right|Cu$, when an external voltage is applied such that $E_{\text{external }}>E_{\text{cell }}$, current flows from_________

• A. Zn to Cu
• B. Cu to Zn
• C. No current flows
• D. data insufficient

Answer 1

Answer: (A)

On applying an external voltage greater than $1.1V$ in a Daniell cell, the current flows in the reverse direction i.e., from $Zn$ to $Cu$ (cathode to anode) and electrons flow from $Cu$ to $Zn$.
$Zn$ is deposited at $Zn$ electrode and $Cu$ dissolves at Cu electrode. The reaction is
$Z{n}^{2+}+Cu\to Zn+C{u}^{2+}$