Question

Which of the following statements about the monomer and dimer of $N{O}_2$ are not true ?

• A. Both are diamagnetic
• B. Both are paramagnetic
• C. The monomer is paramagnetic and the dimer is not
• D. The dimer is paramagnetic and the monomer is not

Answer 1

Answer: (A), (B), (D)

The correct options are
A Both are diamagnetic
B Both are paramagnetic
D The dimer is paramagnetic and the monomer is not

$N{O}_2$ is an odd electron $(9+8+8=23\text{electrons})$ species with the odd electron present . on the N atom. Hence, it is paramagnetic.

To become more stable, the two odd electrons pair up to form a dimer, which is diamagnetic.

Hence, the correct options are $\text{A}$, $\text{B}$ and $\text{D}$