Question

Dissolving 120 gm of urea (mol. wt. 60) in 1000 gm of water gave a solution of density 1.15 gm/ml. The molarity of the solution is:

• A. $1.78M$
• B. $2.00M$
• C. $2.05M$
• D. $2.22M$

Answer 1

Answer: (C)

$2.05M$

Total mass of solution = 1120g

moles of urea= $\frac{120}{60}=2$

Density = $\frac{mass}{volume}=\frac{1120}{V}$

Molarity = $\frac{moles}{volume}=\frac{2\times 1.15}{1120}\times 1000=2.05M$

Option C is correct.