JEE Main · 2022 · 27 Jul 2022 · Shift 2 · d and f Block Elements

The spin only magnetic moment of the complex present in Fehling's reagent is ____ B.M. (Nearest integer).

Answer: 2

Solution

Fehling's reagent contains a copper(II) complex. The electronic configuration of

Cu X^{2 +}

3 d^{9}

, which has 1 unpaired electron.

The spin-only magnetic moment is calculated using the formula:

μ = n (n + 2) B.M.

where

n

= number of unpaired electrons.

For

n = 1

μ = 1 (1 + 2) = 3 = 1.73 B.M.

Rounding to the nearest integer gives 2 B.M.

JEE Main · 2022 · 27 Jul 2022 · Shift 2 · Integer answer