Question
Which from following pair of elements in their respective oxidation states develops same value of calculated spin only magnetic moment ?
MHT CET
Chemistry
d and f Block Elements
2026
MHT CET 2026 (17 April Shift 2)
MHT CET Chemistry Question (2026) — Solution
Options
- A. Ti ^ 3+ and Zn ^ 2+
- B. Cr ^ 2+ and Fe ^ 2+
- C. Cr ^ 3+ and Ti ^ 3+
- D. Zn ^ 2+ and Cu ^ 2+
Answer
B. Cr ^ 2+ and Fe ^ 2+
Step-by-step solution
The spin-only magnetic moment is given by = n(n+2) BM, where n is the number of unpaired electrons. Electronic configuration of Ti ^ 3+ is [ Ar ] 3d^ 1 , so n = 1. Electronic configuration of Zn ^ 2+ is [ Ar ] 3d^ 10 , so n = 0. Electronic configuration of Cr ^ 2+ is [ Ar ] 3d^ 4 , so n = 4. Electronic configuration of Fe ^ 2+ is [ Ar ] 3d^ 6 , so n = 4. Electronic configuration of Cr ^ 3+ is [ Ar ] 3d^ 3 , so n = 3. Electronic configuration of Cu ^ 2+ is [ Ar ] 3d^ 9 , so n = 1. Since both Cr ^ 2+ and Fe ^ 2+ have 4 unpaired electrons, they will have the same calculated spin-only magnetic moment of 4(4+2) = 24 BM. Answer: Cr ^ 2+ and Fe ^ 2+
Related: Chemistry — d and f Block Elements · All PYQ Banks