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The number of paramagnetic species from the following is ______. [Ni(CN)4]2−, [Ni(CO)4], [NiCl4]2−, [Fe(CN)6]4−, [Cu(NH3)4]2+, [Fe(H2O)6]2+ and [Fe(H2O)6]3+

1. 1
2. 2
3. 3
4. 4

Correct answer: 3

Solution

The correct option is 3 because among the given complexes, [Fe(H2O)6]2+, [Fe(H2O)6]3+, and [Cu(NH3)4]2+ contain unpaired electrons, making them paramagnetic, while the others are either diamagnetic or have all paired electrons.

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