A 69.4 L cylinder containing C2H6 at a pressure of 570 torr is connected by a valve to 105 L cylinder containing C6H6 at 0.350 atm pressure. Calculate the partial pressure (atm) of C6H6 when the valve is opened.

Answer 1

The question is about partial pressure of C6H6 and Dalton's Law tells us that gases act independently in mixtures; therefore, just ignore the C2H6 (but not the container). Then, for C6H6,
P1V1 = P2V2
You know P1 and V2 for C6H6. P2 is what you are looking for and V2 is just the sum of the two volumes of the containers.