PHYSICAL CHEMISTRY - Gaseous State

Matter exist in three states - solid , liquid, or gas. A solid possesses definite shape and definite volume. It also possesses definite geometry with orderly array of atoms, molecules or ions in the structure. The constituents of solid are held close together by strong attractive forces. A liquid, on the other hand, has a definite volume but no definite shape. The constituents of a liquid are held by molecular forces, which are not so strong as in a solid. A gas has neither definite shape nor definite volume. In gaseous state, the molecular forces are much weaker. Gaseous state is the simplest state of matter.

Gases are Generally Classified two Category:-

1. Ideal Gas

2. Non-Ideal Gas

Important Law's Used in the Gaseous State :-

1. Boyle's Law :- This law was first given by Robert Boyle's in 1662. The law is based upon the series of experimentsin which he observed the effect of pressure on the volume of a given amount of air at constant temprature. On the basis of result he put forward a law known as Boyle's law, the law is stated as :
" At constant temprature, the volume of a given mass of a gas is inversely proportional to its pressure."

2. Charle's Law :- This law is given by charles in 1787. Charle's law stated as :-
"Pressure remaing constant, the volume of a given mass of a gas increase or decrease by 1/273 of its volume at 0*C for every degree rise or fall temprature."

3. Avogadro's Law :- Avogadro in 1811 suggested that "equal volume of different gases at the same temprature and pressure contain equal number of molecules."