2.50 L of gas originally at 50 K is warmed to 80 K. If the pressure remains constant, which gas law needs to be used to find the new volume?

A : Charles Law

B : Combined Gas Law

C : Boyle's Law

D : Gay-Lussac's law

A

Explanation:

You want an equation that includes both V and T. Charles' Law states that V = kT or V₁/T₁ = V₂/T₂, so this is the best formula to use.

B: The Combined Gas Law is p₁V₁/T₂ = p₂V₂/T₂ will work, but it's overkill for the situation. You can assume any constant value for the pressure, and it will cancel from each side of the equation,

C is wrong. Boyle's Law is p₁V₁ = p₂V₂. It does not include the temperature.

D is wrong. Gay-Lussac's Law is p₁/T₂ = p₂/T₂. It does not include the volume.