A sample of gas has an initial volume of 22.2 L at a pressure of 1.57 atm. If the sample is compressed to a volume of 10.2 L , what is its pressure? (Assume constant temperature.)

Question

Please explain thoroughly

Answer 1

Constant temperature = Boyles Law

Boyles Law: P1V1 = P2V2

P1 = initial pressure = 1.57 atm

V2 = initial volume = 22.2 L

P2 = final pressure = ?

V2 = final volume = 10.2 L

Plug in the values and solve for P2

(1.57 atm)(22.2 L) = (x atm)(10.2 L)

x = 3.42 atm = final pressure

Explanation:

When the temperature is constant, and assuming the moles of gas hasn't changed either, then the only variables left to consider are pressure and volume. If you decrease the volume, the pressure has to increase because there's less room for the gas molecules to move around in, and so the collide with the sides of the container more (that's what pressure is), and so pressure goes up. Vice versa if the volume were to increase.