Question

Which of the following properties is not shown by NO?
(IIT-JEE, 2014)

• A. It combines with oxygen to form nitrogen dioxide
• B. It's bond order is 2.5
• C. It is diamagnetic in gaseous state.
• D. It is a neutral oxide.

Answer 1

The correct option is C It is diamagnetic in gaseous state.

(a), (b) and (d) are correct but (c) is incorrect.

:N = O:

NO is paramagnetic in gaseous state due to the presence of unpaired electron in its structure and is neutral oxide.

Calculation of bond order:
Total number of electrons = 7 + 8 = 15
Remaining p electrons = 15 - 8 = 7
$N_b$ = 6, Na = 1.
B.O. = $\frac{1}{2}(6-1)=2.5$