Final answer:
Charles' law states that the volume of an ideal gas varies directly with its temperature when other properties remain constant. Mathematically, it is represented as V/T = constant at constant P and n.
Step-by-step explanation:
Charles' law: The volume (V) of an ideal gas varies directly with the temperature of the gas (T) when the pressure (P) and the number of moles (n) of the gas are constant.
We can express this mathematically as: V/T = constant at constant P and n.
If either volume or temperature changes while pressure and amount of gas stay the same, then the other property must change so that the ratio of volume to temperature still equals the same constant. That is, if the original conditions are labeled V₁ and T₁ and the new conditions are labeled V₂ and T₂, we have: V₁/T₁ = V₂/T₂ at constant P and n.