Question

Why is `["Mo"("H"_2"O")_6]^(3+)` paramagnetic?

Answer 1

`[Mo(OH_2)_6]^(3+)` is a paramagnet due to the electronic configuration of the metal ion.

Explanation:

The `Mo^(3+)` is a `d^3` ion. Coordination chemistry would predict that the `d` electrons were all unpaired, and therefore give rise to paramagnetism. Even if only 1 of the electrons were unpaired (which is a necessity!) the complex would still be a paramagnet).