Q: Ethylene glycol is mixed with the water in the car radiator to prevent freezing. Ff the mixture is 40% water and 60% ethylene glycol, which substance is the solvent and which is the solute?

Flexi Says: The molecular weight of ethylene glycol and water is 62 g/mol and 18 g/mol respectively. Since it is 60% of ethylene glycol, thus its number of moles = 0.6/62 = 0.009. Similarly, number of moles of water = 0.4/18 = 0.022. Thus, the mole fraction of ethylene glycol = 0.009/0.009 + 0.022 = 0.3 while that for water is 0.7. Therefore, the solvent is water in the solution since its mole fraction is higher than ethylene glycol.