Let the mass of the solution is 100g The mass of H2O=25g mass of ethanol =25g mass of acetic acid =50g Number of moles of water =25g/18g/mol=1.4 Number of moles of ethanol = 25g46g/mol=0.54 Number of moles of Acetic acid =50g60g/mol=0.8 Total number of moles =(1.4+0.54+0.8)=2.74 Now, the mole fraction of water =1.4/2.74=0.51 mole fraction of Ethanol =0.54/2.74=0.197 mole fraction of acetic acid =0.8/2.74=0.291