When matter is transformed from the liquid state to the gas state, what happens to the distance and attraction between particles?

2 Answers
Oct 9, 2016

The distance between the particles increase tremendously the attraction doesn't change.


One mole of any gas will occupy the molar volume of 22.4 liters of volume or 22400 ml of volume.

As a liquid one mole of water occupies 18 ml of volume. As a gas at 22400 ml it increases its volume by 1244.4 times.

The attraction of the particles between the water molecules stays the same regardless of the physical state of the water, solid, liquid or gas.

The difference is the kinetic energy of the molecules. As a liquid the molecules do not have enough kinetic energy to break the intermolecular bonds that hold the molecules loosely together.

As a gas the molecules have more kinetic energy and the attraction between the molecules is not strong enough to hold the molecules together at the higher levels of molecular motion due to the increased kinetic energy.

Oct 28, 2016

The distance between the particles increases greatly, and the attractive forces between the particles decreases.



For example, 1 mol (18 g) of water occupies a volume of #"18 cm"^3#.

If we convert the water to steam at 1 atm and 100 °C, it occupies a volume that is 1700 times greater.

The distance between molecules has increased greatly.

Attractive Forces

The nature of the attractive forces does not change in the solid, liquid, or gas: it is an electrical attraction between charges.

The force of the attraction #F# is given by Coulomb's Law:

#color(blue)(bar(ul(|color(white)(a/a) F = (kq_1q_2)/d^2color(white)(a/a)|)))" "#


#k# = a proportionality constant
#q_1, q_2# = the charges
#d# = the distance between them

The attractive forces are inversely proportional to the square of the distance between the particles.

The particles in a gas are much further from each other than in a liquid, so the attractive forces between them are quite weak.