QJEEM22Chd682: JEE Main 2022 Chemistry - Class 12 JEEM22Chd682 Solution: The number of statements correct from the following for Copper…

(A) $\mathrm{Cu}$ (II) complexes are always paramagnetic as they have one unpaired electron due to $d^{9}$ configuration of $\mathrm{Cu}(\mathrm{II})$

(B) $\mathrm{Cu}(\mathrm{I})$ complexes are generally colourless due to $d^{10}$ configuration.

(C) $\mathrm{Cu}(\mathrm{I})$ is easily oxidised to $\mathrm{Cu}^{+2}$ in aqueous solution

$2 \mathrm{Cu}^{+} \rightarrow \mathrm{Cu}^{+2}+\mathrm{Cu}$

$\mathrm{Cu}^{+1}$ disproportionates to $\mathrm{Cu}^{+2}$ and $\mathrm{Cu}$

\left(E_{\text {cell }}^{\circ}>0\right. for this cell reaction in aqueous solution)

In Fehling's solution, active reagent has $\mathrm{Cu}(\mathrm{II})$ which is reduced to $\mathrm{Cu}(\mathrm{I})$ on reaction with aldehydes.

Hence (D) statement is incorrect