Question

Part 1 of 3:
An apparatus consists of a 2 L flask containing nitrogen gas at 30 degrees C and 758 kPa, joined by a valve to a 11 L flask containing argon gas at 30 degrees C and 49.7 kPa. The valve is opened and the gases mix. What is the partial pressure of nitrogen after mixing?
Answer in units of kPa
Part 2 of 3:
What is the partial pressure of argon after mixing?
Answer in units of kPa
Part 3 of 3:
What is the total pressure of the gas mixture?
Answer in units of kPa

Answer 1

The long way of doing this, but the easier to explain, is as follows.
Use PV = nRT and solve for n N2 in the 2L tank.
Use PV = nRT and solve for n Ar in the 11 L tank.
Then add nN2 + nAr = nTotal and
use PV = nRT with a volume of 13 L (the sum of the 11 and 2 L tanks). That gives you #3 answer.

Then for PN2 after mixing use PV = nRT and use nN2 for n and use 13 for Vtotal.

Do the same thing for pAr but use nAr and 13 L