The mole fraction of C₂H₅OH (Mol. wt. = 46) in 5 molal aqueous ethyl alcohol solution is

5 moles solution of 2 5 C H OH contains 5 moles of 2 5 C H OH in 1kg of water We know that 1kg of water contains 55.5 moles of water. Then mole fraction of ethanol is, 2 5 5 Mole fraction of C H OH 5 55.5 Therefore, 2 5 0.082 C H OH X