Charles’ Law Experiment for Schools, Teachers, and Students
Charles’ Law states that the volume of a fixed amount of gas is directly proportional to its absolute temperature, provided the pressure remains constant.
Mathematically:
V ∝ T
or
V/T = constant
Where:
- V: Volume of the gas (in m³ or L)
- T: Absolute temperature of the gas (in Kelvin)
- Pressure and the amount of gas remain constant.
Equation of Charles’ Law:
For two states of the gas at constant pressure:
V1/T1 = V2/T2
Where:
- V1, T1: Initial volume and temperature
- V2, T2: Final volume and temperature
Graphical Representation of Charles’ Law:
- Volume-Temperature Graph (V-T): The graph of volume (V) vs. absolute temperature (T) is a straight line passing through the origin.
- Extrapolation to Absolute Zero: When the temperature is extrapolated to 0 K (absolute zero), the volume theoretically becomes zero.
Key Points:
- Volume increases as temperature increases, provided pressure is constant.
- At absolute zero (0 K), the volume of an ideal gas is theoretically zero.
- Charles’ law applies only when the gas behaves ideally and pressure is constant.
Real-Life Applications of Charles’ Law:
- Hot Air Balloons: As the air inside a balloon is heated, its temperature increases, causing the air to expand, and the balloon rises.
- Car Tires: On a hot day, the air inside car tires expands, increasing the volume or pressure.
- Helium Balloons in Cold Weather: Helium balloons shrink when exposed to cold temperatures because the volume decreases as temperature drops.
- Temperature Compensation in Gas Meters: Gas meters account for changes in volume with temperature using Charles’ law.
Observations:
- When the temperature of a gas increases, its volume increases at constant pressure.
- When the temperature decreases, the volume decreases proportionally.
- Absolute zero (0 K) is the theoretical point where the gas volume becomes zero.
Charles’ law establishes the relationship between the temperature and volume of a gas under constant pressure. It highlights that gas volume expands or contracts linearly with temperature changes.
