Q1(b). Magnetic moment of titanium(III)

Answer in brief

Ti³⁺ is d¹, with one unpaired electron: μso = √3 = 1.73 μB. Spin–orbit coupling modifies the spin-only value.

Key points

• Oxidation state: three K⁺ require [TiF₆]³⁻; x − 6 = −3, so x = +3.
• Configuration: Ti³⁺ has one 3d electron. In an octahedral field it occupies t₂g: t₂g¹ eg⁰.
• Spin-only formula: μso = √[n(n + 2)] μB = √[1(1 + 2)] μB = 1.73 μB.
• The orbitally degenerate t₂g ground state permits residual orbital angular momentum and spin–orbit coupling.
• For this less-than-half-filled d shell, coupling can lower the effective moment; 1.70 μB is close to the spin-only prediction.