Pair of transition metal ions having the same number of unpaired electrons is
- Ti3+, Mn2+
- Ti2+, Co2+
- Fe3+, Cr2+
- V2+, Co2+
Answer
(4) V2+, Co2+
Solution
(A) Ti3+: 3d1 → 1 unpaired; Mn2+: 3d5 → 5 unpaired
(B) Ti2+: 3d2 → 2 unpaired; Co2+: 3d7 → 3 unpaired
(C) Fe3+: 3d5 → 5 unpaired; Cr2+: 3d4 → 4 unpaired
(D) V2+: 3d3 → 3 unpaired; Co2+: 3d7 → 3 unpaired
V2+ and Co2+ both have 3 unpaired electrons.
Answer: (4)