The mole fraction of urea in an aqueous solution is 0.1 . If the density of the solution is 1.11 ~g/mL , the molarity of the solution is :

Step-by-step solution

Let the total moles of the solution mixture be 1 ~mol . Moles of urea (solute) = 0.1 ~mol Moles of water (solvent) = 1 - 0.1 = 0.9 ~mol Molar mass of urea = 60 ~g/mol Molar mass of water = 18 ~g/mol Mass of urea = 0.1 60 = 6 ~g Mass of water = 0.9 18 = 16.2 ~g Total mass of the solution = 6 + 16.2 = 22.2 ~g Volume of the solution = Mass Density = 22.2 1.11 = 20 ~mL Molarity is the number of moles of solute per liter of solution : Molarity = Moles of solute Volume of solution in mL 1000 Molarity = 0.1 20 1000 = 5 ~M