Question

Which statement explains why low temperature and high pressure are required to liquefy chlorine gas?
(1) Chlorine molecules have weak covalent bonds.
(2) Chlorine molecules have strong covalent bonds.
(3) Chlorine molecules have weak intermolecular forces of attraction.
(4) Chlorine molecules have strong intermolecular forces of attraction.

Answer 1

Answer: (3) Chlorine molecules have weak intermolecular forces of attraction.

Explanation: In order to liquefy a gas, the molecules must be brought closer. Chlorine being a gas has weak inter molecular forces of attraction and the molecules are far away from each other.

Thus decreasing the temperature would decrease the kinetic energy of the molecules and increase in pressure would bring the molecules close together to convert it into  liquid phase.