Question

What is the relationship with temp., pressure and volume when looking at states of matter and phase changes?

Answer 1

There are basically 3 states of matter namely , solid , liquid and gas.

The major difference between these phases is the arrangement of their particles.

In solids , the particles are very tightly packed , In liquids the particles are comparatively loose and in gases the particles are very far apart.

Solids and liquids have fixed volumes as they have stronger intermolecular forces in between the particles , whereas gases do not have specific volume as they have minimal attractive forces in between their particles.

Solids tend to melt at high temperatures , as the particles gain kinetic energy to overcome the intermolecular forces, and become liquid . Likewise the liquids vaporise at higher temperatures to become gas.

The reverse happens when the temperature is lowered , Gases condense into liquids and liquids into solids.

The particles of solid are packed under high pressure , so when the pressure is lowered they tend to convert into liquids and then gases . Again the reverse is seen when the pressure is increased , the gases pressurise to become liquids and liquids pressure to become solids under high pressure.