The volume, V of gas varies inversely with the Pressure, P on it. If the volume is 320 cm3 under pressure of 40 kg/cm2, what pressure has to be applied to have a volume of 200 cm3?

Assuming that the gas behaves ideally.

Given the initial volume and pressure:

V1 = 320 cm3

P1 = 40 kg/cm2

and given the final volume:

V2 = 200 cm3

find the final pressure, P2:

PV = nRT; assume temperature and number of moles are constant

PV = constant

P1V1 = P2V2

Solve for P2:

(320 cm3) (40 kg/cm2) = (200 cm3) (P2)

P2 = 64 kg/cm2