Boyle's Law and Isothermal Compression Mechanics

• Gases exhibit large intermolecular spaces and negligible intermolecular cohesive forces compared to liquids and solids, rendering them highly compressible.
• Robert Boyle established that for a fixed quantity of gas at constant temperature:

P ∝ 1 / V ==> P × V = Constant.

If the pressure upon an enclosed gas is doubled, its volume is halved because the gas molecules are compressed into half the space, doubling the collision frequency against the container walls per unit area.

Graphically: A plot of Pressure (P) versus Volume (V) yields a rectangular hyperbola (isotherm). A plot of Pressure (P) versus reciprocal volume (1/V) yields a straight line passing through the origin with a slope equal to P.V = n R T.