A 5.00 L volume of methane gas is cooled from 298 K to 149 K. If the pressure remains constant, what is the final volume in liters?

The final volume of methane gas = 2.5 L

Explanation:

Charles' Law: Charles' law states that the volume of a given mass of gas is directly proportional to it's absolute temperature provided the pressure remains constant.

From Charles' law

V₁/T₁ = V₂/T₂

Making V₂ The subject of the equation above,

V₂ = (V₁/T₁) T₂ ... equation 1

Where V₁ = initial Volume, T₁ Initial Temperature, V₂ = Final Volume, T₂ = final Temperature.

Given: V₁ = 5.00 L, T₁ = 298 K, T₂ = 148 K

Substituting these values into equation 1

V₂ = (5.00/298) 149

V₂ = 2.5 L.

Therefore the final volume of methane gas = 2.5 L