Which of the following statements is correct for the cell \(\mathrm{Zn}\left|\mathrm{Zn}^{+2} \|…
Which of the following statements is correct for the cell \(\mathrm{Zn}\left|\mathrm{Zn}^{+2} \| \mathrm{Cu}^{+2}\right| \mathrm{Cu}\) ?
\(\mathrm{Zn}\) is reducing agent.
Cu is anode.
\(\mathrm{Cu}\) is oxidising agent.
The cell reaction is \(\mathrm{Zn}+\mathrm{Cu}^{+2} \longrightarrow \mathrm{Zn}^{+2}+\mathrm{Cu}\)
Solution
In the Daniell cell, copper and zinc electrodes are immersed in a solution of copper(II) sulphate and zinc sulphate, respectively.
At the anode (negative electrode), zinc is oxidised per the following half reaction.
\(\mathrm{Zn}(s) \longrightarrow \mathrm{Zn}^{2+}(a q)+2 e^{-}\)
At the cathode (positive electrode), copper is reduced per the following reaction.
\(\mathrm{Cu}^{2+}(a q)+2 e^{-} \longrightarrow \mathrm{Cu}(s)\)
Overall cell reaction is
\(\mathrm{Zn}(s)+\mathrm{Cu}^{2+}(a q) \longrightarrow \mathrm{Zn}^{2+}(a q)+\mathrm{Cu}(s)\)
These processes result in the accumulation of solid copper at the cathode and the corrosion of the zinc electrode into the solution as zinc cations. Hence, the correct option is (d).