Question

Determine the partial pressures and the total pressure in a 2.50-L vessel containing the following mixture of gases at 17.8°C: 0.0254 mol He, 0.0571 mol H2, and 0.189 mol Ne. Also what is the partial total.

Answer 1

total mole = sum of moles of all gases = 0.0254 + 0.0571 + 0.189 =0.2715 mole

Calulate total pressure by using ideal gas equation

Ideal gas equation

PV = nRT             where, P = atm pressure= ?

V = volume in Liter = 2.50 L

n = number of mole = 0.2715 mol

R = 0.08205L atm mol^-1 K^-1 =Proportionality constant = gas constant,

T = Temperature in K = 17.8⁰C = 273.15+ 17.8 = 290.95 K

We can write ideal gas equation

P = nRT/V

Substitute value in above equation

P = 0.2715X 0.08205 X 290.95 / 2.50 = 2.5925 atm

Total pressure = 2.5925 atm

now calculate mole fraction of individual gases

mole fraction = no. of mole of insivisual gas / total mole

mole fraction of He = 0.0254 / 0.2715 = 0.094

mole fraction of H₂ = 0.0571 / 0.2715 = 0.210

mole fraction of Ne = 0.189 / 0.2715 = 0.696

now calulate partial pressure of indivisual gas

partial pressure = mole fraction X  total pressure

partial pressure of He = 0.094 X 2.5925 = 0.2437 atm

partial pressure of H₂ = 0.210X 2.5925 = 0.5444atm

partial pressure of Ne = 0.696 X 2.5925 = 1.8043 atm