Question

A mixture of gases contains methane, CH4, ethane, C2H6, and propane, C3H8. If the total pressure is 1.5 atm and the number of moles of the gases present is .31 mole for methane, .25 mole for ethane, and .29 mole for propane, calculate the partial pressure for the gases.

Answer 1

The partial pressure  for the gases is as below

CH₄=0.547  atm

C₂H₆= 0.441 atm

C₃H₈ =0.512 atm

calculation

 partial  pressure of a  gas=[ (moles  of the gas/ total   moles) x  total pressure]

Total  moles = moles of (  CH₄ + C₂H₆ + C₃H₈)  =0.31 + 0.25 +0.29 = 0.85  moles

Total pressure = 1.5 atm

partial pressure  for CH₄ = (0.31/0.85)  x 1.5 atm=0.547 atm

Partial  pressure for C₂H₆ =( 0.25 /0.85)  x 1.5 atm = 0.441 atm

partial  pressure for C₃H₈ =(0.29/0.85)  x 1.5 atm =0.512 atm