Question

A mixture of 2.00 moles of H₂, 3.00 moles of NH₃, 4.00 moles of CO₂ and 5.00 moles of N₂ in a 15.0L container at 18⁰C What is the total pressure and the partial pressure of each gas?

PV=nRT is the equation i'm using

R=0.08206

I need to convert C to K, find the moIes in grams of each, the use formula for each compund, the total masses and do the same, correct?

I think I have this figured out, but I would like to check my answers. Please post work so I can compare, thank you

This is what I came up with, I don't think my answer is correct, total = 429, H2 = 6.42, NH3 = 81.4, CO2 = 280, N2 = 223. These don't add up to my total pressure. Welp, back to the books...

Answer 1

At the same pressure and temperature, all gases exert the same pressure if moles are the same.

Total moles = 2.00 + 3.00 + 4.00 + 5.00 = 14.0 moles

Volume = 15.0 L

Temperature = 180 C = 453 K

Total pressure = moles * R * temperature / volume

= 15.0 mole * 0.0821 L-atm/mol. K * 453 K / 15.0 L = 37.2 atm

Mole fraction of each gas = moles/ total moles

MF of H2 = 2.00 mol / 15.0 mol = 0.133

MF of NH3 = 3.00/ 15.0 = 0.200

MF of CO2 = 4.00 / 15.0 = 0.27

MF of N2 = 5.00 / 15.0 = 0.33

Partial pressure of each gas = MF * total pressure

Pressure of H2 = 0.133 * 37.2 = 4.95 atm

Pressure of NH3 = 0.200 * 37.2 = 7.44 atm

Pressure of CO2 = 0.27 * 37.2 = 10.0 atm

Pressure of N2 = 0.33 * 37.2 = 12.3 atm