Given below are two statements : 1 M aqueous solution of each of $\mathrm{Cu}\left(\mathrm{NO}_3\right)_2,…

Given below are two statements :
1 M aqueous solution of each of $\mathrm{Cu}\left(\mathrm{NO}_3\right)_2, \mathrm{AgNO}_3$, $\mathrm{Hg}_2\left(\mathrm{NO}_3\right)_2 ; \mathrm{Mg}\left(\mathrm{NO}_3\right)_2$ are electrolysed using inert electrodes,
$\begin{aligned} & \text { Given : } \mathrm{E}_{\mathrm{Ag}^{+} / \mathrm{Ag}}^\theta=0.80 \mathrm{~V}, \mathrm{E}_{\mathrm{Hg}_2^{2+} / \mathrm{Hg}}^\theta=0.79 \mathrm{~V}, \\ & \mathrm{E}_{\mathrm{Cu}^{2+} / \mathrm{Cu}}^\theta=0.24 \mathrm{~V} \text { and } \mathrm{E}_{\mathrm{Mg}^{2+} / \mathrm{Mg}}^\theta=-2.37 \mathrm{~V}\end{aligned}$
Statement (I) : With increasing voltage, the sequence of deposition of metals on the cathode will be $\mathrm{Ag}, \mathrm{Hg}$ and Cu
Statement (II) : Magnesium will not be deposited at cathode instead oxygen gas will be evolved at the cathode.
In the light of the above statement, choose the most appropriate answer from the options given below
  1. Both statement I and statement II are incorrect
  2. Statement I is correct but statement II is incorrect
  3. Both statement I and statement II are correct
  4. Statement I is incorrect but statement II is correct

Solution

Statement-II $\Rightarrow$ At cathode, instead of $\mathrm{Mg}, \mathrm{H}_2 \mathrm{O}_{(\ell)}$ will reduce \& evolve $\mathrm{H}_2$ gas.

Asked in: JEE Main 2025 (07 Apr Shift 2)

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