Question

To prevent a condition called the “bends,” deep-sea divers breathe a mixture containing, in the mole percent, 10.0% Oz , 10.0% N2 , and 80.0% He. What is the partial pressure of each gas if the total pressure is 825 mm Hg? please explain or show steps. thanks

Answer 1

mass of O2 = 10.0 g

moles of O2 = 10 / 32 = 0.3125

moles of N2 = 10 / 28 = 0.357

moles of He = 80 / 4 = 20

total moles = 20 + 0.357 + 0.3125 = 20.67

mole fraction of O2 = 0.3125 / 20.67 = 0.015

mole fraction of N2 = 0.357 / 20.67 = 0.0173

mole fraction of He = 20 / 20.67 = 0.968

total pressure = 825 mmHg

partial pressure = mole fraction x total pressure

partial pressure of O2 = 0.015 x 825 = 12.38 mmHg

partial pressure of N2 = 14.27 mmHg

partial pressure of He = 798.6 mmHg