JEE Advanced · Chemistry · 2. Atomic Structure
Assuming that Hund's rule is violated, the bond order and magnetic nature of the diatomic molecule \(\mathrm{B}_2\) is
- A 1 and diamagnetic
- B 0 and diamagnetic
- C 1 and paramagnetic
- D 0 and paramagnetic
Answer & Solution
Correct Answer
(A) 1 and diamagnetic
Step-by-step Solution
Detailed explanation
\(\mathrm{B}_2\) : Total electrons \(=10\)
Configuration : \(\sigma 1 s^2 \sigma^* 1 s^2 \sigma 2 s^2 \sigma^* 2 s^2 \pi 2 p_x^1=\pi 2 p_y^1\)
If Hunds rule is violated, then
\(\sigma 1 s^2 \sigma^* 1 s^2 \sigma 2 s^2 \sigma^* 2 s^2 \quad \pi 2 p_x^2=\pi 2 p_y^0\)
So, diamagnetic
\(\text {Bond order }=\frac{6-4}{2}=1\)
Chemical bonding
Conceptual
\(\text{II}\)
Configuration : \(\sigma 1 s^2 \sigma^* 1 s^2 \sigma 2 s^2 \sigma^* 2 s^2 \pi 2 p_x^1=\pi 2 p_y^1\)
If Hunds rule is violated, then
\(\sigma 1 s^2 \sigma^* 1 s^2 \sigma 2 s^2 \sigma^* 2 s^2 \quad \pi 2 p_x^2=\pi 2 p_y^0\)
So, diamagnetic
\(\text {Bond order }=\frac{6-4}{2}=1\)
Chemical bonding
Conceptual
\(\text{II}\)
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