Question

Which of the following pairs of molecules will have permanent dipole moments for both members?

• A. $N{O}_{2}andC{O}_2$
• B. $N{O}_{2}and{O}_3$
• C. $Si{F}_{4}andC{O}_2$
• D. $Si{F}_{4}andN{O}_2$

Answer 1

The correct option is B $N{O}_{2}and{O}_3$

$Si{F}_4$, $C{O}_2$ are perfectly symmetrical molecules.

Here, the dipole in all the directions cancel out and the resultant dipole is zero.

Resonance takes place in both $N{O}_2$ and $O_3$.

The partial charges in both the molecules cause individual dipoles to exist which in turn creates a permanent dipole moment.

Therefore, the option is B.