Question

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

(a) 1.78 M

(b) 2.00 M

(c) 2.05 M

(d) 2.22 M

Answer 1

Correct option is (c) 2.05 M

Answer 2

Correct option is (c) 2.05 M

 \(V_{sol}=\frac{(120+1000)}{1.15}mL\)

\(M=\frac{W_2\times1000}{Mw_2\times V_{sol}}\) \(=\frac{120\times1000}{60\times\frac{1120}{1.15}}\) \(=\frac{2\times115}{112}=2.05M.\)