A 150.0 mL cylinder containing CO at a pressure of 9.50 atm is connected by a valve to 9500 mL cylinder containing B5H9 at 2280 torr pressure. Calculate the partial pressure (atm) of B5H9 when the valve is opened.
You want to know about B5H9; therefore, you can ignore the CO. The B5H9 will go from a volume of 9500 mL to a total volume of (9500+150) mL. Use
P1V1 = P2V2, solve for V2 and convert to atm.