The density of a solution prepared by dissolving 120 g urea (mol. mass = 60 g/mol) in 1000 g of water is 1.15 g/ml. What is the molarity of the solution?
Answer & explanation
Correct answer: option 1
Mass of solution = 1000 + 120 = 1120 g
Volume of solution = \(\frac{mass}{density}\) = \(\frac{1120}{1.15}\)ml
Moles of urea = \(\frac{120}{60}\) = 2
Molarity = \(\frac{\text{Moles of urea}}{Volume}\)x1000
= \(\frac{2}{1120/1.15}\) x 1000 = 2.05 M