Gay-Lussac’s Law describes the relationship between the pressure and temperature of a gas when the volume is held constant. The law states that the pressure of a gas is directly proportional to its temperature (in Kelvin) when the volume is constant. The variables in Gay-Lussac’s Law are:
1. **Pressure (P):** This is the force exerted by the gas per unit area. It is typically measured in atmospheres (atm), Pascals (Pa), or millimeters of mercury (mmHg).
2. **Temperature (T):** This is the measure of the average kinetic energy of the gas particles. It must be measured in Kelvin (K) for the law to hold true.
3. **Volume (V):** Although the volume is held constant in Gay-Lussac’s Law, it is still an important variable to consider. The volume is the space that the gas occupies, usually measured in liters (L) or cubic meters (m³).
Mathematically, Gay-Lussac’s Law can be expressed as:
P₁/T₁ = P₂/T₂
Where:
– P₁ and P₂ are the initial and final pressures of the gas.
– T₁ and T₂ are the initial and final temperatures of the gas in Kelvin.
This law is useful in various applications, such as predicting how the pressure of a gas will change with temperature in a sealed container.