1. All the three N—O bond lengths in HNO₃ are not equal. Double bonds are generally smaller in size than single bond.

2. All P—Cl bond lengths in PCl5 molecule in gaseous state are not equal. Axial bonds are larger than equatorial bonds.

3. ) P4 molecule in white phosphorous have angular strain therefore white phosphorus is very reactive.

4.) PCl is ionic in solid state in which cation is tetrahedral and anion is octahedral.

Cation [PCl₄]⁺

Anion [PCl₆]^-