Boyle's Law

Boyle's law: at constant temperature, pressure × volume = constant. PV = const.

Equivalently: P₁V₁ = P₂V₂ for an ideal gas at constant T.

Inverse proportionality between P and V.

On PV diagram: hyperbola (also an isotherm).

Experimentally verified by Robert Boyle (1662) using mercury and air in a J-tube.

Microscopically: smaller V ⇒ same molecules hit walls more often ⇒ higher pressure.

Real gases deviate at high P (intermolecular forces, molecular size).

Special case of ideal gas law (PV = nRT) at constant n and T.