An 1.04-L sample of gas at 759 mm Hg pressure

expanded until its volume is 2.24 L. What

the pressure in the expanded gas sample

at constant temperature) ?

PV = nRT

where P is the pressure,

V is the volume,

n is the moles of gas,

R is the gas constant,

and T is the temperature.

We must relate this equation to a sample of gas at two different volumes however. Looking at the equation, we can relate the change in volume by:

P1V1 = P2V2

where P1 is the initial pressure,

V1 is the initial volume,

P2 is the final pressure,

and V2 is the final volume.

Looking at this relationship, pressure and volume have an indirect relationship; when one goes up, the other goes down. In that case, we can use this equation to solve for the new pressure.

P1V1 = P2V2

(759 mm Hg) (1.04 L) = P2 (2.24 L)

P2 = 352 mm Hg (rounded to three significant figures)