Q. Given below are two statements: Statement I: Both $\left[Co(NH_3)_6\right]^{3+}$ and $\left[CoF_6\right]^{3-}$ complexes are octahedral but differ in their magnetic behaviour. Statement II: $\left[Co(NH_3)_6\right]^{3+}$ is diamagnetic whereas $\left[CoF_6\right]^{3-}$ is paramagnetic. In the light of the above statements, choose the correct answer from the options given below:
A) Statement I is true but Statement II is false.
B) Statement I is false but Statement II is true.
C) Both Statement I and Statement II are true.
D) Both Statement I and Statement II are false.
Explanation
[Solution by Claude - not from source] $NH_3$ is strong-field (low-spin $d^6$, diamagnetic); $F^-$ is weak-field (high-spin, 4 unpaired e$^-$, paramagnetic). Both statements are true. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.