Question

A sample of neon gas at 20 °C is confined to a cylinder with a movable piston. The gas is then heated until its pressure is doubled. What is the final temperature of the gas?

Answer 1

P1 * V1 * T1 = P2 * V2* T2

Where:
P1=initial pressure
V1 = initial volume
T1 = initial temperature
(and the other three variables correspond to the final pressure, volume, and temperature).

In order to solve the equation, you need to know 5 of the values and then solve for the sixth.
You only know T1=20, P1=1, P2=2. You need to know V1 and V2 to solve for T2.

so, the answer is temperature T2 cannot be found since the final and iniinitial volumes are unknown.

This is Boyle's Law.