JEE Main 2022 — Coordination Compounds Question with Solution

Fehling's solution consists of two parts A and B.  Fehling’s solution A  is deep blue colour due to the bis(tartrate) complex of ${\mathrm{Cu}}^{2+}$. Fehling's solution B is the Rochelle salt (potassium sodium tartrate tetrahydrate) serves as a chelating agent in the solution.

Fehling solution is a complex of ${\mathrm{Cu}}^{++}$

${\mathrm{Cu}}^{++}=3 {\mathrm{d}}^9$

Number of unpaired ${\mathrm{e}}^{-}=1$

$\mathrm{Magnetic} \mathrm{Moment}=\sqrt{1\left(1+2\right)}=\sqrt{3}=1.73\mathrm{BM}$