Given E deg(Cu^+/Cu) = +0.52 V and E deg(Cu^2+/Cu^+) = +0.16 V, which statement about Cu^+ in aqueous solution at 298 K (standard conditions) is correct?

It disproportionates to Cu^2+ and Cu with E deg_cell = +0.36 V

It is stable because E deg_cell for disproportionation is -0.36 V

It disproportionates to Cu^2+ and Cu with E deg_cell = +0.36 V

It disproportionates with E deg_cell = +0.68 V

It disproportionates with E deg_cell = +0.16 V

JEE Main levelSingle correct optionDifficulty 2 of 3df061

Given $E^{\circ} (Cu X^{+} / Cu) = + 0.52 V$ and $E^{\circ} (Cu X^{2 +} / Cu X^{+}) = + 0.16 V$ , which statement about $Cu X^{+}$ in aqueous solution at 298 K (standard conditions) is correct?

AIt is stable because $E_{cell}^{\circ}$ for disproportionation is $- 0.36 V$
BIt disproportionates to $Cu X^{2 +}$ and $Cu$ with $E_{cell}^{\circ} = + 0.36 V$
CIt disproportionates with $E_{cell}^{\circ} = + 0.68 V$
DIt disproportionates with $E_{cell}^{\circ} = + 0.16 V$

For

2 Cu X^{+} \to Cu X^{2 +} + Cu

Cu X^{+}

is reduced at the cathode (

0.52 V

) and oxidised at the anode (

0.16 V

E_{cell}^{\circ} = 0.52 - 0.16 = + 0.36 V > 0

, so the reaction is spontaneous and

Cu X^{+}

is unstable in water.