Ideal Gas and Laws obeyed by Ideal Gas

Ideal Gas

A gas which does not changes its phase and obeys all the gas laws at all value of temperature and pressure is called ideal gas.

Various laws that must be obeyed by an ideal gas.

1. Boyle’s Law

2. Charles’s Law

3. Gay Lussac's Law

1. Boyle’s Law – As per this law pressure is inversely proportional to volume at constant temperature during any change of state.

Mathematically P α 1/V (at const. temp.)

P/V = C

If a system goes from state 1 to state 2 at constant temperature then as per Boyle’s Law

P1 V1 = C

P2 V2 = C

Therefore P1 V1 = P2 V2 (at const. temperature)

Fig. P-V diagram and P-T diagram

2. Charles’s Law – As per this law volume is directly proportional to temperature at constant pressure during any change of state.

Mathematically V α T (at const. pressure)

V/T = C (at const. pressure)

If a system goes from state 1 to state 2 at constant pressure then as per Charles’s Law

V1/T1 = C

V2/T2 = C

V1/T1 = V2/T2 = C (at const. pressure)

Fig. P-V diagram, P-T diagram and V-T diagram

3. Gay Lussac's Law – As per this law pressure is directly proportional to temperature when the volume is kept constant during any change of state.

Mathematically P α T (at const. volume)

P/T = C

If a system goes from state 1 to state 2 at constant volume then as per Gay Lussac's Law

P1/T1 = C

P2/T2 = C

P1/T1 = P2/T2 = C (at const. volume)

Fig. P-V diagram, P-T diagram and T-V diagram