Question

The complex showing a spin-only magnetic moment of 2.82 B.M. is:

• A. \( \text{Ni(CO)}_4 \)
• B. \( [NiCl_2]^{2-} \)
• C. \( \text{Ni(PPh}_3)_4 \)
• D. \( [Ni(CO)_3]^{2-} \)

Hint:

The spin-only magnetic moment is calculated using the number of unpaired electrons in the complex. The formula \( \mu = \sqrt{n(n+2)} \) is useful for determining magnetic moments.

Answer 1

The Correct Option is C

Step 1: The spin-only magnetic moment \( \mu_{\text{sp}} \) is given by: \[ \mu_{\text{sp}} = \sqrt{n(n+2)}, \] where \( n \) is the number of unpaired electrons. The value of 2.82 B.M. corresponds to \( n = 2 \), indicating that the complex has two unpaired electrons.
Step 2: The complex \( \text{Ni(PPh}_3)_4 \) has the required configuration to give the spin-only magnetic moment of 2.82 B.M.

Final Answer: \[ \boxed{\text{Ni(PPh}_3)_4} \]