Answer: mole fractions are
For n-pentane = 0.965
For n-octane = 0.035
Explanation: pressure exerted by each gas is,
n-pentane = 1.92atm
n-octane = 0.07atm
Total pressure exerted = 1.92 + 0.07
= 1.99atm.
Recall that the partial pressure exerted by each gas is the product of its mole fraction and the total pressure, that is,
Pres. n-pentane = n x pressure(total)
1.92 = n x 1.99
n = 1.92/1.99 = 0.965 for n-pentane
For n-octane,
n = 1 - 0.965 = 0.035 for n-octane.
