Question

A sample of oxygen gas occupies a volume of 365.2 mL. When the volume is increased to 478.2 mL, the new pressure is 241.3 torr. What was the original pressure?

Answer 1

Boyle's law states the relationship between pressure and volume in gases.
It states that at constant temperature, pressure of a gas is inversely proportional to its volume.
PV = k
where P - pressure, V - volume and k - constant
P1V1 = P2V2
parameters for the 1st instance are in the left side and parameters for the second instance are on the right side
P1 x 365.2 mL = 241.3 torr x 478.2 mL
P1 = 316.0 torr