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 of this solution is :

• A. $0.50\, M$
• B. $1.78\, M$
• C. $1.02\, M$
• D. $2.05\, M$

Answer 1

Answer: (D)

$2.05\, M$

Answer 2

Molarity $= \frac{mols\, of\, solute}{volume \,of \,sol. \left( \ell\right)}$ $= \frac{120 \times1.15}{60 \times1120} \times1000 = 2.05\,M$