# CHARLES' LAW

#### branchTHERMAL PHYSICS

Coming from GASES
Leading to THE IDEAL GAS LAW
Charles's law (also known as the law of volumes) is an experimental gas law which describes how gases tend to expand when heated. A modern statement of Charles's law is: ===When the pressure on a sample of a dry gas is held constant, the Kelvin temperature and the volume will be directly related.=== this directly proportional relationship can be written as: $$V \propto T$$ or $$\frac{V}{T}=k$$ where: V is the volume of the gas T is the temperature of the gas (measured in Kelvin). k is a constant. This law describes how a gas expands as the temperature increases; conversely, a decrease in temperature will lead to a decrease in volume. For comparing the same substance under two different sets of conditions, the law can be written as: $$\frac{V_1}{T_1} = \frac{V_2}{T_2} \qquad \mathrm{or} \qquad \frac {V_2}{V_1} = \frac{T_2}{T_1} \qquad \mathrm{or} \qquad V_1 T_2 = V_2 T_1$$ [image:http://upload.wikimedia.org/wikipedia/commons/thumb/e/e4/Charles_and_Gay-Lussac%27s_Law_animated.gif/300px-Charles_and_Gay-Lussac%27s_Law_animated.gif]
Credit: Tristan O'Hanlon