Moles of compound
Given:
Mass percentage of ethylene glycol (C2H6O2) in a solution=20%
i.e., 100 g of solution contains 20 g of ethylene glycol and 82 g of water.
Molar mass of C2H6O2=12×2+1×6+16×2=62 g mol−1
Moles of C2H6O2=mass of C2H6O2Molar mass of C2H6O2=20g62 gmol−1
=0.322mol
Similarly, moles of water =80g18 gmol−1=4.444mol
Mole fraction of ethylene glycol
xglycol=moles of C2H6O2moles of C2H6O2+moles of H2O
=0.322 mol0.322 mol+4.444 mol=0.068