Question

Calculate the mole fraction of Ethylene glycol (C2H6O2) in a solution containing 20% of C2 H6 O2 by mass

Answer 1

Dear student,

20% of C₂H₆O₂ by mass is present.
That means solution has 20 g of ethylene glycol and 80 g of water.
Now,
Molar mass of C₂H₆O₂ = (12 x 2) + (1 x 6 )+ (2 x 16) = 62 g mol^-1 .
Moles of C₂H₆O₂ = 20 / 62 = 0.322 moles
Moles of water = 80 / 18 = 4.444 moles
Mole fraction of ethylene glycol = 0.322 /( 0.322 + 4.444) = 0.068

Regards.