Question

Among the following ions, which one has the highest paramagnetism?

• A. [Cr(H2O)6]3+
• B. [Fe(H2O)6]2+
• C. [Cu(H2O)6]2+
• D. [Cu(H2O)6]2+

Answer 1

Answer: (B)

$Fe(H2O)6$2+

Answer 2

(1) Cr3+, 3d3

n = 3.

(2) Fe2+, 3d5

n = 5.

It has maximum number of unpaired electrons.

(3) Cu2+, 3d9

n = 0.

(4) Zn2+, 3d10

n = 0.