A 275-mL f lask contains pure helium at a pressure of 752 torr. A second f lask with a volume of 475 mL contains pure argon at a pressure of 722 torr. If the two f lasks are connected through a stopcock and the stopcock is opened, what is the partial pressure of each gas and the total pressure?

The partial pressure of Helium is 275.7 torr

The partial pressure of argon is 457.3 torr

The total pressure is 733 torr

Explanation:

Step 1: Data given

Volume helium flask = 275 mL = 0.275L

Pressure in helium flask = 752 torr

Volume argon flask = 475 mL = 0.475 L

Pressure in argon flask = 722 torr

Step 2: Calculate the total volume of the gas mixture once the stopcock is opened.

Total volume = volume of Helium flask + volume argon flask

Total volume = 275 + 475 = 750 mL = 0.750 L

Step 3: Calculate partial pressure of Helium

pHe * VHe = p'He * Vtotal

⇒ with pHe = the pressure of Helium = 752 torr

⇒ with VHe = the volume in the helium flask = 275 mL

⇒ with p'He = the partial pressure of helium = To be determined

⇒with Vtotal = the total volume = 750 mL

p'He = (pHe*VHe) / Vtotal

p'He = (752*275) / 750

p'He = 275.7 torr

Step 4: Calculate partial pressure of Argon

pAr * VAr = p'Ar * Vtotal

⇒ with pAr = the pressure of Argon = 722 torr

⇒ with VAr = the volume in the Argon flask = 475 mL

⇒ with p'Ar = the partial pressure of argon = To be determined

⇒with Vtotal = the total volume = 750 mL

p'Ar = (pAr * VAr) / Vtotal

p'Ar = (722*475) / 750

p'Ar = 457.3 torr

Step 5: Calculate the total pressure

Total pressure = partial pressure Helium + partial pressure Argon

Total pressure = 275.7 torr + 457.3 torr = 733 torr