Answer:
Partial pressure of O₂ = 0.0198 atm
Partial pressure of He = 0.1584 atm
Step-by-step explanation:
Given data:
Mass of oxygen = 80.0 g
Mass of helium = 80.0 g
Total pressure = 0.1800 atm
Partial pressure of each gas = ?
Solution:
First of all we will calculate the number of moles.
Number of moles of oxygen:
Number of moles = mass/molar mass
Number of moles = 80.0 g/ 32 g/mol
Number of moles = 2.5 mol
Number of moles of helium:
Number of moles = mass/molar mass
Number of moles = 80.0 g/ 4 g/mol
Number of moles = 20 mol
Total number of moles = 20 mol + 2.5 mol = 22.5 mol
Mole fraction of O₂ = 2.5 mol/ 22.5 mol = 0.11
Mole fraction of He = 20 mol / 22.5 mol = 0.88
Partial pressure:
Partial pressure of O₂ = 0.11× 0.1800 atm = 0.0198 atm
Partial pressure of He = 0.88 × 0.1800 atm = 0.1584 atm