Question

Which gas law states that the volume of a gas is directly proportional to its temperature?

Answer 1

If it's an Ideal Gas then it's : `PV=nRT or V=(nRT)/P`

Explanation:

For Ideal Gas : `PV=nRT or V=(nRT)/P`
P : Pressure `(Pa)`
V : Volume `(m^3)`
n : amount of substance of the gas `(mol)`
R : gas constante `(8.314 J.K^-1.mol^-1)`
T : absolute temperature `(K)`
(SI base unit)

Answer 2

I have a different answer.
Charles's law, an experimental gas law, describes how gases tend to expand on heating.

Explanation:

Charles's law, which is also know as Law of Volumes, states that

For a sample of a dry gas, its volume and Kelvin temperature are directly related, provided pressure is held constant.

Mathematically relationship can be written as

`V prop T`

or `V=kT`,

where `V` is the volume of the sample of gas, `T` its temperature in Kelvin and `k` is constant of proportionality.

Alternatively it can be written as
`V_1/T_1=V_2/T_2`