an aqueous solution is 0.40 mole fraction solution of methanol in water complete the table and calculate m

Answer 1

0.4 = (moles of methanol) / (moles of methanol + moles of water). Let's make up numbers and make (moles of methanol + moles of water) =100 moles. If this is the case, there is 40 moles of methanol (since 40/100 = 0.4). Now, we can figure out how many moles of water there are (100 moles total - 40 moles methanol = 60 moles water).

m (molality) = moles of solute / kg of solvent

solute = methanol

solvent = water (H₂O)

We already know that there is 40 moles of methanol. We have 60 moles of water and we can convert this to grams:

60 mols H₂O x (18 g H₂O/1 mol H₂O) = 1080 grams H₂O = 1.08 kg H₂O

Now, you can put everything into the molality equation.

m = 40 mols methanol / 1.08 kg water = 37.037037... --> put it into 2 sig figs and you get 37 m.