Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

If the two flasks are connected through a stopcock and the stopcock is opened, w

ID: 574582 • Letter: I

Question

If the two flasks are connected through a stopcock and the stopcock is opened, what is the partial pressure of helium?P_He: ?

If the two flasks are connected through a stopcock and the stopcock is opened, what is the partial pressure of argon?P_Ar: ?

If the two flasks are connected through a stopcock and the stopcock is opened, what is the total pressure?

P_total: ?

A 285-mL flask contains pure helium at a pressure of 755 torr. A second flask with a volume of 495 mL contains pure argon at a pressure of 713 torr

Explanation / Answer

total volume = 285 + 495 = 780 mL

for Helium :

P1 = 755 torr   ; V1 = 285 mL

P2 = ??       ; V2 = 780 mL

P2 = P1 x V1 / V2

     = 755 x 285 / 780

P2 = 276 torr

pressure of He = 276 torr

for Argon :

P2 = 713 x 495 / 780

     = 452.5

pressure of Ar = 452 torr

Ptotal = 728 torr