Question

The pair in which both species have same magnetic moment (spin only value) is

Answer 1

The correct option is (b).

Explanation:

Spin only magnetic moment, U_s = √n(n+2) where, n = number of unpaired electrons. 

Number of unpaired electrons in Cr²⁺ ([Ar] 3d⁴) is 4, in Co²⁺ ([Ar]3d⁷) is 3, in Fe²⁺ ([Ar] 3d⁶) is 4, in Mn²⁺ ([Ar] 3d⁵) is 5. 

As the number of unpaired electrons in Cr²⁺ and Fe²⁺ are same, hence [Cr(H₂O)₆]²⁺ and [Fe(H₂O)₆]²⁺ will have same magnetic moment.