When a supply of hydrogen gas is held in a 4 liter container at 320 K it exerts a pressure of 800 torr. The supply is moved to a 2 liter container, and cooled to 160 K. What is the new pressure of the confined gas?

1 Answer
Dec 19, 2014

The answer is P2=800 torr.

The best way to approach this problem is by using the ideal gas law, PV=nRT. Since the hydrogen is moved from a container to another, we presume that the number of moles remains constant. This will give us 2 equations

P1V1=nRT1 and P2V2=nRT2. Since R is a constant as well, we can write

nR=P1V1T1=P2V2T2 the combined gas law.

Therefore, we have

P2=V1V2T2T1P1=4L2L160K320K800torr=800torr.