Home › UP Board Class 12 › Redox & Electrochemistry › In a Daniell cell, $\mathrm{Zn} | \mathrm{Zn}^{2…
In a Daniell cell, $\mathrm{Zn} | \mathrm{Zn}^{2+}(aq) \,||\, \mathrm{Cu}^{2+}(aq) | \mathrm{Cu}$, the standard EMF is calculated as:
A$E^\circ_{\mathrm{Cu}^{2+}/\mathrm{Cu}} + E^\circ_{\mathrm{Zn}^{2+}/\mathrm{Zn}}$
B$E^\circ_{\mathrm{Zn}^{2+}/\mathrm{Zn}} - E^\circ_{\mathrm{Cu}^{2+}/\mathrm{Cu}}$
C$E^\circ_{\mathrm{Cu}^{2+}/\mathrm{Cu}} - E^\circ_{\mathrm{Zn}^{2+}/\mathrm{Zn}}$
D$\dfrac{1}{2}\left(E^\circ_{\mathrm{Cu}^{2+}/\mathrm{Cu}} + E^\circ_{\mathrm{Zn}^{2+}/\mathrm{Zn}}\right)$
Answer & Solution
Correct answer: C. $E^\circ_{\mathrm{Cu}^{2+}/\mathrm{Cu}} - E^\circ_{\mathrm{Zn}^{2+}/\mathrm{Zn}}$
$E^\circ_\text{cell} = E^\circ_\text{cathode} - E^\circ_\text{anode}$ where both standard electrode potentials are written as reduction potentials. Copper is the cathode (reduction $\mathrm{Cu}^{2+} + 2e^- \to \mathrm{Cu}$) and zinc is the anode in a Daniell cell.
Related questions
Iron rusting on the village ploughshare is best described as:Electrolysis of molten NaCl at the electrode passes $1$ F of charge. The amount of Na depoThe Nernst equation at $25^\circ$C for a cell with $n$ electrons transferred is $E = E^\ciIn a Daniell cell with Zn (anode) and Cu (cathode), and $E^\circ(Cu^{2+}/Cu) = +0.34$ V, $When zinc is added to $\mathrm{CuSO_4}$ copper gets ppt. due to$\mathrm{CrO}_4^{2-}$ (yellow) changes to $\mathrm{Cr}_2\mathrm{O}_3^{2-}$ (orange) in What would be the product of electrolysis if molten $\mathrm{ICl}_3$ is electrolysed?Which of the following ion is expected to have highest value of molar conductivity at infi