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The metal ions that have the calculated spin only magnetic moment value of 4.9 B.M. are A. Cr2+ B. Fe2+ C. Fe3+ D. Co2+ E. Mn3+ Choose the correct answer from the options given below: (1) B and E only (2) A, B and E only (3) A, D and E only (4) A, C and E only

1. B and E only
2. A, B and E only
3. A, D and E only
4. A, C and E only

Correct answer: A, B and E only

Solution

The calculated spin-only magnetic moment of 4.9 B.M. corresponds to a specific number of unpaired electrons, which is found in the configurations of Cr2+, Fe2+, and Mn3+. These ions have the right electron arrangements to yield this magnetic moment, while the others do not.

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