Question

Cupric compounds are more stable than their cuprous counterparts in solid state. This is because

• A. the endothermic character of the $2^{nd}$ $IP$ of $Cu$ is not so high
• B. size of $Cu^{2+}$ is less than $Cu^+$
• C. $Cu^{2+}$ has stabler electronic configuration as compared to $Cu^+$
• D. the lattice energy released for cupric compounds is much higher than $Cu^+$

Answer 1

Answer: (A), (B), (D)

Electronic configurations of cuprous $\left( Cu ^{+}\right)$and cupric $\left( Cu ^{2+}\right)$ ions are as follows
$ Cu ^{+}=[ Ar ] 3 d^{10} \,4 s^{\circ} $
$Cu ^{2+} =[ Ar ] 3 d^{9} \,4 s^{0}$
Thus, electronic configuration of $Cu ^{+}$is more stable but it is less stable because in $Cu ^{2+}$ due to its small size the nuclear charge is sufficient to hold $27$ electrons but in $Cu ^{+}$such a condition is not true.
Further, the IInd IP of $Cu$ is not very high as compared to its $Ist$ IP. Consequently a large amount of lattice energy is released for cupric compounds as compared to $Cu ^{+}$compounds.