Question

Liquid water is about 800 times denser than dry air under standard conditions. Use kinetic molecular theory to explain this difference in the densities of the two substances.

Answer 1

According to kinetic molecular theory, there is little attraction between gas molecules and the size of the gas particles is small compared to the amount of space they take up. Because the particles are so far apart in a gas, the density of a gas is low under standard conditions. On the other hand, the attractions between the particles in a liquid hold the particles close together. Because there is little empty space between the particles of a liquid, liquids are much denser than gases under standard conditions.