Identify the incorrect statement from the options below for the above cell :
Question:

Identify the incorrect statement from the options below for the above cell :

  1. If $\mathrm{E}_{\text {ext }}>1.1 \mathrm{~V}, \mathrm{e}^{-}$flows from $\mathrm{Cu}$ to $\mathrm{Zn}$

  2. If $\mathrm{E}_{\text {ext }}>1.1 \mathrm{~V}, \mathrm{Zn}$ dissolves at $\mathrm{Zn}$ electrode and $\mathrm{Cu}$ deposits at $\mathrm{Cu}$ electrode

  3. If $E_{\text {ext }}<1.1 \mathrm{~V}, \mathrm{Zn}$ dissolves at anode and $\mathrm{Cu}$ deposits at cathode

  4. If $E_{\text {ext }}=1.1 \mathrm{~V}$, no flow of $e^{-}$or current occurs


Correct Option: , 2

Solution:

$\mathrm{E}_{\text {cell }}^{0}=\mathrm{E}_{\mathrm{Cu}^{2+}}^{0}{\mid \mathrm{Cu}}^{-}-\mathrm{E}_{\mathrm{Zn}^{2+} \mid \mathrm{Zn}}^{0}=1.1 \mathrm{~V}$

So, if $\mathrm{E}_{\text {ext. }}=1.1 \mathrm{~V}$ no electron will flow

At, $\mathrm{E}_{\text {ext. }}>1.1 \mathrm{~V}$ cell act as electrolytic cell and electron will flow from $\mathrm{Cu}$ to $\mathrm{Zn}$.

At, $\mathrm{E}_{\text {ext. }}<1.1 \mathrm{~V}$ cell act as electrochemical cells so $\mathrm{Zn}$ dissolve and $\mathrm{Cu}$ deposit.

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