Question

The pair having the same magnetic moment is: [At. No.: Cr = 24, Mn = 25, Fe = 26, Co = 27]

(1) [Cr(H2O)6]2+ and [Fe(H2O)6]2+

(2) [Mn(H2O)6]2+ and [Cr(H2O)6]2+

(3) [CoCl4]2– and [Fe(H2O)6]2+

(4) [Cr(H2O)6]2+ and [CoCl4]2–

Answer with reason ✌✌​

Answer 1

Answer:

The pair having the same magnetic moment is

[Cr(H2O)6]2+ and [Fe(H2O)6]2+

In [Cr(H2O)6]2+ , the chromium metal is in +2 oxidation state with 3d4 outer electronic configuration and 4 unpaired electrons.

In [Fe(H2O)6]2+ , the iron metal is in +2

oxidation state with 3d6 outer electronic configuration and 4 unpaired electrons.

Since both complexes have same number of unpaired electrons, they have the same magnetic moment.

Hope it helps

Answer 2

Answer:

Explanation:

magnetic moment \mu = \sqrt {n \left ( n+2 \right )} where n is the number of unpaired electrons.

In given problem Cr^{2+} and Fe^{2+} has same number of unpaired electrons

Cr^{2+} => 3d^{4} four unpaired electrons

Fe^{2+} => 3d^{6} four unpaired electrons

Correct answer is 2