Question

Given below are two statements:
Statement I: Both [Co(NH₃)₆]³⁺ and [CoF₆]^3- complexes are octahedral but differ in their magnetic behaviour.
Statement II: [Co(NH₃)₆]³⁺ is diamagnetic whereas [CoF₆]^3- is paramagnetic.
In the light of the above statements, choose the correct answer from the options given below:

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is true but Statement II is false
• D. Statement I is false but Statement II is true

Answer 1

The Correct Option is A

Step 1: Analyze [Co(NH₃)₆]³⁺

In this complex, Co³⁺ is in a strong field generated by NH₃ (a strong ligand). The strong field forces electron pairing, resulting in a diamagnetic complex.

Step 2: Analyze [CoF₆]³⁻

In this complex, Co³⁺ is in a weak field generated by F⁻ (a weak ligand). The weak field does not induce electron pairing, resulting in a paramagnetic complex.

Step 3: Evaluate Statements

• Statement I: True — Both complexes possess an octahedral geometry but exhibit distinct magnetic properties.
• Statement II: True — [Co(NH₃)₆]³⁺ is diamagnetic, whereas [CoF₆]³⁻ is paramagnetic.

Conclusion

The accurate assessment of the complexes' magnetic behavior substantiates that:

Both Statement I and Statement II are verified as true.