When an aqueous solution of $\mathrm{CuCl}_2$ is electrolysed using Pt inert electrodes, the reaction at…

When an aqueous solution of $\mathrm{CuCl}_2$ is electrolysed using Pt inert electrodes, the reaction at cathode and anode respectively are
  1. $4 \mathrm{H}_2 \mathrm{O}(f) \stackrel{+4 \mathrm{a}^{-}}{\longrightarrow} 2 \mathrm{H}_2(g)+4 \mathrm{OH}_2(\mathrm{aq})$; $$ 2 \mathrm{H}_2 \mathrm{O}(l) \stackrel{-4 \mathrm{a}^{-}}{\longrightarrow} \mathrm{O}_2(g)+4 \mathrm{H}^{+}(\mathrm{aq}) $$
  2. $2 \mathrm{Cu}^{2 *}(\mathrm{aq}) \stackrel{+\mathrm{se}^{-}}{\longrightarrow} 2 \mathrm{Cu}(\mathrm{s})$; $$ 2 \mathrm{H}_2 \mathrm{O}(l) \stackrel{-4 \mathrm{~s}^{-}}{\longrightarrow} \mathrm{O}_2(g)+4 \mathrm{H}^*(a q) $$
  3. $\mathrm{Cu}^{2 *}(\mathrm{aq}) \stackrel{+2 \mathrm{a}^{-}}{\longrightarrow}, \mathrm{Cu}(\mathrm{s}) ; 2 \mathrm{Cl}^{-}(\mathrm{aq}) \stackrel{-2 \mathrm{a}^{-}}{\longrightarrow} \mathrm{Cl}_2(\mathrm{~g})$
  4. $2 \mathrm{H}_2 \mathrm{O}(f) \stackrel{+2 \mathrm{a}^{-}}{\longrightarrow} \mathrm{H}_2(g)+2 \overline{\mathrm{O}} \mathrm{H}(\mathrm{aq})$; $$ 2 \mathrm{Cl}^{-}(a q) \stackrel{-2 \mathrm{an}^{-}}{\longrightarrow} \mathrm{Cl}_2(g) $$

Solution

$ \text { } \mathrm{CuCl}_2 \longrightarrow \mathrm{Cu}^{2+}(a q)+2 \mathrm{Cl}^{-}(a q) $ $\mathrm{Cl}^{-}$show oxidation at anode and form $\mathrm{Cl}_2$ gas. $ 2 \mathrm{Cl}^{-} \stackrel{-2}{2} \stackrel{e^{-}}{\longrightarrow} \mathrm{Cl}_2(g) $ Due to less reactivity, $\mathrm{Cu}^{2+}$ gain electrons and deposited at cathode electrode. $ \mathrm{Cu}^{2+}+2 e^{-} \longrightarrow \mathrm{Cu} $

Asked in: AP EAMCET 2018 (22 Apr Shift 1)

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