1. The problem statement, all variables and given/known data The molality of an aqueous sodium nitrate solution is 2.14 m. What is the mole fraction of sodium nitrate? 2. Relevant equations Molality = moles of solute / kg of solvent. Mole fraction of A = moles of A / total number of moles (in this case, moles of solute + moles of solution). 3. The attempt at a solution Assuming we have 1 kg of solvent, we can assume we have 2.14 moles of NaNO3. Mole fraction of NaNO3 is therefore 2.14 / [(1000/18) + 2.14] = 0.0370. 1000/18 because 1000 grams of water is present and there are 18 grams per mole of water. The grams cancel out and yield moles of water.