Question

The following gases are mixed in a 10.0L fixed volume flask: 2.0L of H2 at 1.0 atm, 8.0L of N2 at 3.0 atm, and 4.0L of Ar at 0.5 atm. What is the final total pressure and partial pressure of each of the gases?

Answer 1

Final total pressure P = P1V1 + P2V2 + P3V3 / V

Given that 2.0L of H2 at 1.0 atm, 8.0L of N2 at 3.0 atm, and 4.0L of Ar at 0.5 atm are mixed in 10 L flask.

V1 P1 V2 P2 V3 P3 V

Hence,

P = P1V1 + P2V2 + P3V3 / V = [ (1 atm x2 L) + (3 atm x8 L) + ( 0.5 atmx 4 L)] / 10 L

= 2.8 tm

Therefore, Final total pressure = 2.8 atm

Partial pressure of H2 = P1V1/ V = (1 atm x2 L) / 10 L = 0.2 atm

Partial pressure of N2 = P2V2/ V = (3 atm x 8 L) / 10 L = 2.4 atm

Partial pressure of Ar = P3V3/ V = (0.5 atm x 4 L) / 10 L = 0.2 atm