In the Daniell cell, \(\mathrm{Zn}\left|\mathrm{Zn}^{2+} \| \mathrm{Cu}^{2+}\right| \mathrm{Cu}\), when an…
In the Daniell cell, \(\mathrm{Zn}\left|\mathrm{Zn}^{2+} \| \mathrm{Cu}^{2+}\right| \mathrm{Cu}\), when an external voltage is applied such that \(E_{\text {external }}>E_{\text {cell }}\), current flows from.........
\(\mathrm{Zn}\) to \(\mathrm{Cu}\)
Cu to \(\mathrm{Zn}\)
no current flows
data insufficient
Solution
On applying an external voltage greater than \(1.1 \mathrm{~V}\) in a Daniell cell, the current flows in the reverse direction i.e., from \(\mathrm{Zn}\) to \(\mathrm{Cu}\) (cathode to anode) and electrons flow from \(\mathrm{Cu}\) to \(\mathrm{Zn}\).
\(\mathrm{Zn}\) is deposited at \(\mathrm{Zn}\) electrode and \(\mathrm{Cu}\) dissolves at \(\mathrm{Cu}\) electrode. The reaction is
\(\mathrm{Zn}^{2+}+\mathrm{Cu} \longrightarrow \mathrm{Zn}+\mathrm{Cu}^{2+}\)