Question

Dissolving 120 gm of a compound of (mol. wt. 60) in 1000 g of water gave a solution of density 1.5 g/mL. The molarity of the solution is:

• A. $1.00M$
• B. $1.78M$
• C. $2.50M$
• D. $4.00M$

Answer 1

Answer: (C)

$2.50M$

Total mass of solution = 1120g

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

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

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