Calculation Mole Fractions

Gabriel Hannawi

Ethylene glycol (C2H6O2) is added to automobile cooling systems to protect against cold weather. What is the mole fraction of each component in a solution containing 1.25 mol of ethylene glycol (EG) and 4.00 mol of water?

Knowns:• Moles of EG (nEG)=1.25 mol EG• Moles of water=4.00 mol H2OUnknowns:• Mole fraction EG• Mole fraction H2O

Knowns:• Moles of EG (nEG)=1.25 mol EG• Moles of water=4.00 mol H2O

Unknowns:• Mole fraction EG• Mole fraction H2O

XEG=1.25 mol/(1.25 mol+4.00 mol)=0.238XH2O=4.00mol/(1.25 mol +4.00 mol)=0.762

XEG=nEG/(nEG+nH2O)XH2O=nH2O/(nEG+nH2O)

Practice Problems

• What is the mole fraction of each component in a solution made by mixing 300g of ethanol (C2H5OH) and 500 g of water?

• A solution contains 50.0g of carbon tetrachloride and 50.0g of chloroform(CHCl3). Calculate the mole fraction of each component in the solution