Question

A flask of unknown volume was filled with air at a pressure of 389.0 kPa. The flask was attached to an evacuated flask of 32.0 L and the air was allowed to expand into the second flask. At equilibrium, the final pressure was 154.0 kPa. Calculate the volume of the unknown flask.

Answer 1

(a) Use Boyle's law to calculate the volume the gas will occupy if the pressure is increased to 1.79 atm while the temperature is held constant.


3.17 L

(b) Use Charles's law to calculate the volume the gas will occupy if the temperature is increased to 175°C while the pressure is held

Answer 2

Intuitively you see that the pressure has decreased which means the volume must have increased; therefore, the volume of the old flask is v and the volume of the combined flasks is 32+v
Since p1v1 = p2v2, then
389*v = 154(32+v) and solve for v.