Question

1 kg of an aqueous urea solution having mole fraction 0.2 is diluted to 5kg. What is the mole fraction of solute in diluted solution?

Answer 1

Let mass of  be  (gm) in 1 molal solution.

Then  (Molar mass of  is )

Hence  

Now diluted solution weighs . Upon dilution, number of moles of glucose (or mass of glucose) remains unchanged. Hence the mass of solvent becomes