Question

Which one of the following sets CORRECTLY represents the increase in the paramagnetic property of the ions?

Options

• Mn²⁺ > Cr⁺ > V²⁺

• Cr²⁺ < V²⁺ < Mn²⁺

• V²⁺ < Cr²⁺ < Mn²⁺

• V²⁺ < Mn²⁺ < Cr²⁺

Answer 1

V²⁺ < Cr²⁺ < Mn²⁺

Explanation:

V: [Ar] 3d³ 4s²

V²⁺: [Ar] 3d³ 4s⁰

∴ 3 unpaired electrons

Cr: [Ar] 3d⁵ 4s¹

Cr²⁺: [Ar] 3d⁴

∴ 4 unpaired electrons

Mn: [Ar] 3d⁵ 4s²

Mn²⁺: [Ar] 3d⁵

∴ 5 unpaired electrons

Greater the number of unpaired electrons, greater will be its paramagnetic property. Hence the order of increase in the paramagnetic property is: V²⁺ < Cr²⁺ < Mn²⁺.