Question

A mixture of gases contains 0.320 mol CH4, 0.240 mol C2H6, and 0.300 mol C3H8. The total pressure is 1.45 atm. Calculate the partial pressures of the gases.

Answer 1

pCH₄ = 0.540 atm

pC₂H₆ = 0.405 atm

pC₃H₈ = 0.505 atm

Step-by-step explanation:

Step 1: Calculate the total number of gaseous moles

n = n(CH₄) + n(C₂H₆) + n(C₃H₈)

n = 0.320 mol + 0.240 mol + 0.300 mol = 0.860 mol

Step 2: Calculate the partial pressure of each gas

We will use the following expression.

pi = P × Χi

where,

• pi: partial pressure of the gas "i"

• P: total pressure

• Χi: mole fraction of the gas "i"

pCH₄ = 1.45 atm × 0.320 mol/0.860 mol = 0.540 atm

pC₂H₆ = 1.45 atm × 0.240 mol/0.860 mol = 0.405 atm

pC₃H₈ = 1.45 atm × 0.300 mol/0.860 mol = 0.505 atm