Rajasthan BoardEnglish MediumSTD 12 ScienceChemistryElectrochemistry1 Mark
Question
Can you store copper sulphate solutions in a zinc pot?
✓
Answer
$Zn$ being more reactive than $Cu,$ displaces $Cu$ from $\ce{CuSO_4}$ solution as follows:
$\ce{Zn (s) + CuSO_4 (aq) \rightarrow ZnSO_4(ag) + Cu (s)}$
In terms of $\text{EMF},$ we have
$\ce{Zn|Zn^{2+}||Cu^{2+}|Cu}$
$\text{E}^\circ_\text{cell}=\text{E}^\circ_{\text{Cu}^{2+}\text{Cu}}-\text{E}^\circ_{\text{Zn}^{2+}/\text{Zn}}$
$= 0.34 V - (-0.76 V)$
$= 1.10 V$
As $\text{E}^\circ_\text{cell}$ is positive, reaction takes place.
i.e., $Zn$ reacts with copper and hence, we cannot store $\ce{CuSo_4}$ solution in zinc pot.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.