Question

The density of a solution prepared by dissolving 120 g of urea (mol. Mass=60 u) in 1000 g of water is 1.15 g/mL. The molarity if this solution is
A. 2.05 M
B. 0.50 M
C. 1.78 M
D. 1.02 M

Answer 1

Correct Answer - A
Total mass of the solution = 1000 + 120 g =1120 g
:. Volume of the solution
`="mass"/"density"=(1120g)/(1.15 g mL^(-1)) = 974 mL `
Molarity of the solution
`(120//60)/974 xx 1000 M = 2.05 M.`