The correct order of the spin-only magnetic moments of the following complexes is (I) [ Cr H 2 O ) 6 B r 2 (II) N a 4 [ F e C N ) 6 (III) N a 3 Fe C 2 O 4 3 Δ 0 > P (IV) ( E t 4 N ) 2 C o C l 4

Step-by-step solution

Cr H 2 O 6 B r 2 : C r 2 + = Ar 4 s 0 3 d 4 t 2 g 3 e g 1 n = 4 , μ = n ( n + 2 ) = 24 B M N a 4 [ F e ( C N ) 6 ] : F e 2 + = [ A r ] 4 s 0 3 d 6 t 2 g 6 e g 1 n = 0 , μ = 0 N a 3 F e C 2 O 4 3 : F e 3 + = A r 3 d 5 t 2 g 5 e g 0 n = 1 , μ = 3 B M E t 4 N 2 C o C l 4 : C o 2 + = A r 3 d 7 e g 4 t 2 g 3 n = 3 , μ = 15 B M