When a sample of gas has a pressure of 139 mmHg and a volume of 333 mL, what will the pressure be in atmospheres when the volume becomes 0.553 L?

We can use the ideal gas equation which is expressed as PV = nRT. At a constant temperature and number of moles of the gas the product of PV is equal to some constant. At another set of condition of temperature, the constant is still the same. Calculations are as follows:

P1V1 = P2V2

P2 = P1 x V1 / V2

P2 = 139 x. 333 / 0.553

P2 = 83.70 mmHg (1 atm / 760 mmHg) = 0.1 atm