# A container holds three gases: helium, argon, and xenon. The partial pressures are 0.450 atm helium and 0.350 atm argon. The total pressure is 3.00 atm. What is the partial pressure of xenon?

##### 2 Answers
Dec 1, 2014

The sum of the partial pressures is equal to the total pressure. $\text{P"_"total}$ = ${\text{P}}_{1}$ + ${\text{P}}_{2}$ + ${\text{P}}_{3}$... .To calculate the partial pressure of one of the components of a mixture, subtract the sum of known partial pressures of the other components from the total pressure.

Given/Known:

$\text{P"_"He}$ = 0.450atm

$\text{P"_"Ar}$ = 0.350atm

$\text{P"_"total}$ = 3.00 atm

Unknown:
$\text{P"_"Xe}$

Solution: Determine the sum of the partial pressures of helium and argon, then subtract the sum from the total pressure.

The sum of the partial pressures of He and Ar = 0.800atm.

$\text{P"_"Xe}$ = 3.00atm - 0.800 = 2.20atm

Dec 1, 2014

partial pressure = total pressure x mole fraction

for He: mole fraction(A)= 0.45/3=0.15atm
for Ar: mole fraction (B)=0.35/3=0.117atm

sum of mole fractions =1
(C)=1-(0.15+0.117)

partial pressure of Xe= 3 x C
=2.199 atm