Question

a 3.5 liter tank contains 7.3 moles of nitrogen, 5.2 moles of oxygen, 1.5 moles of helium, and 8.1 moles of carbon dioxide at 197°C. calculate the partial pressure of each gas in the mixture

Answer 1

The partial pressure of a gas is given by the equation:
P₁ = P(mole of gas/total moles); where P is the total pressure.

We first solve for total pressure P using the Ideal Gas Law PV=nRT.
P = nRT/V
P = (7.3+5.2+1.5+8.1)mol (0.082057)liter·atm/mol·K (197+273.15)K/(3.5 L)
P = 243.599 atm

Calculating for partial pressures of each gas:
Pnitrogen = (243.599 atm) (7.3/22.1) = 80.46 atm
Poxygen = (243.599 atm) (5.2/22.1) = 57.32 atm
Phelium = (243.599 atm) (1.5/22.1) = 16.53 atm
Pcarbon = (243.599 atm) (8.1/22.1) = 89.28 atm