Question

How do you account for physical state of hydrides of oxygen and sulphur at room temperature?

Answer 1

Oxygen occurs as O2 molecule due to pπ-pπ bonding because of which the intermolecular forces in it are weak van der Waals forces as it is small in size with high electron density which tend to repel the other O2 molecules. As a result it exists as gas.

On the other hand, sulphur does not form strong S=S double bonds hence exists as S8 held together by strong covalent bonds and exists as a polyatomic molecule, in which intermolecular forces are strong so, it exists as a solid.