Charles's Law describes the relationship between the volume and temperature of a gas at constant pressure. According to this law, the volume of a given mass of gas is directly proportional to its absolute temperature (measured in Kelvin) when the pressure remains constant.
Formula
The mathematical expression for Charles's Law is:
\[ \frac{V_1}{T_1} = \frac{V_2}{T_2} \]
Where:
- \( V_1 \) is the initial volume of the gas,
- \( T_1 \) is the initial temperature of the gas (in Kelvin),
- \( V_2 \) is the final volume of the gas,
- \( T_2 \) is the final temperature of the gas (in Kelvin).
Relationship
This law indicates that as the temperature of a gas increases, its volume also increases, provided the pressure remains constant. Conversely, if the temperature decreases, the volume decreases as well. This relationship can be conceptualized quite intuitively: heating a gas causes its particles to move more rapidly, leading to an expansion of the gas and thus an increase in volume.
Important Note
- When using the formula, temperatures must be in Kelvin. To convert Celsius to Kelvin, you can use the formula: \[ K = C + 273.15 \]
Applications
Charles's Law is useful in various scientific fields, including meteorology, engineering, and cooking, wherever gases are involved and temperature and volume changes are relevant.