Boyle's Law is one of the fundamental gas laws in physics and chemistry. It describes the relationship between the pressure and volume of a gas at constant temperature.

Definition of Boyle’s Law:

Boyle’s Law states that the pressure of a given mass of gas is inversely proportional to its volume, provided the temperature remains constant.

Mathematical Expression:

P \propto \frac{1}{V} \quad \text{(at constant temperature)}

or

P_1 V_1 = P_2 V_2

Where:

•  and are the initial pressure and volume

•  and are the final pressure and volume

Key Points:

• Applicable only to ideal gases under isothermal (constant temperature) conditions.

• If volume decreases, pressure increases (and vice versa).

• No change in temperature or quantity of gas during the process.

Graphical Representation:

• Pressure vs. Volume: Hyperbolic curve.

• Pressure vs. 1/Volume: Straight line (direct proportionality).

Real-Life Examples:

1. Syringe: Pulling back the plunger increases volume, lowering pressure and drawing liquid in.

2. Scuba Diving: As a diver descends, the pressure increases, and the volume of air in the lungs decreases.