14
P V
α
1
Where
P = pressure of gas.
V = volume of gas.
When we inhale air, muscles increase the size of chest cavity and expand the
lung that increases their volume thereby reducing pressure inside the lungs. Damage
to the lungs due to infection and pollution would affect pulmonary health of the
affected person.
1.2.1.2 Charles’ Law
Charles’ law states that the volume of gas is directly proportional to the absolute
temperature (Fig. 1.9). Mathematically the law is written as:
V T
α
Where V is the volume of a gas and T is the absolute temperature (details of absolute
temperature is discussed in Chap. 2).
Increase in volume of air due to the warming of air in the respiratory system can
be explained in the light of Charles’s law.
1.2.1.3 Pressure Law
Pressure law states that for a fixed mass and constant volume of an ideal gas, the
pressure is directly proportional to absolute temperature (Fig. 1.10).
1 kg
T = 2X
o C
T = X
o C
1 kg
Fig. 1.9 Schematic depiction of Charles’ law
1 Fundamentals of Chemistry for Environmental and Medical Professionals