The increasing order of magnetic behaviour for following complex is
A. \([Ti(H_2O)_6]^{3+}\)
B. \([V(H_2O)_6]^{3+}\)
C. \([MnCl_4]^{2-}\)
D. \([MnF_6]^{3-}\)
E. \([Cr(H_2O)_6]^{3+}\)
Choose the correct answers from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → A < B < E < D < C
Magnetic moment rises with the number of unpaired electrons, n (μ = √[n(n + 2)] BM). Placing each complex, lowest first:
A. \( \ce{[Ti(H2O)6]^3+} \) — first. Ti (Z = 22) [Ar] 3d2 4s2; \( \ce{Ti^3+} \) 3d1, n = 1 (1.73 BM).
B. \( \ce{[V(H2O)6]^3+} \) — second. V (Z = 23) [Ar] 3d3 4s2; \( \ce{V^3+} \) 3d2, n = 2 (2.84 BM).
E. \( \ce{[Cr(H2O)6]^3+} \) — third. Cr (Z = 24) [Ar] 3d5 4s1; \( \ce{Cr^3+} \) 3d3 (t2g3), n = 3 (3.87 BM).
D. \( \ce{[MnF6]^3-} \) — fourth. x − 6 = −3 gives \( \ce{Mn^3+} \), 3d4; weak-field \( \ce{F-} \), high spin t2g3 eg1, n = 4 (4.90 BM).
C. \( \ce{[MnCl4]^2-} \) — last. x − 4 = −2 gives \( \ce{Mn^2+} \), 3d5; tetrahedral, weak-field \( \ce{Cl-} \), high spin, n = 5 (5.92 BM).
NCERT (2026-27 edition):
Magnetic Properties – …
