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 :

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

Tardigrade Admin · Accepted Answer

Molarity = (mols of solute/volume of sol. ( ℓ)) = (120 ×1.15/60 ×1120) ×1000 = 2.05 M

Q. The density of a solution prepared by dissolving $120 g$ of urea (mol. mass = $60 u$ ) in $1000 g$ of water is $1.15 g / m L$ . The molarity of this solution is :

$0.50 M$

$1.78 M$

$1.02 M$

$2.05 M$

Molarity $= \frac{m o l s o f so l u t e}{v o l u m e o f so l . ( ℓ )}$
$= \frac{120 \times 1.15}{60 \times 1120} \times 1000 = 2.05 M$

Q. The density of a solution prepared by dissolving 120g of urea (mol. mass = 60u) in 1000g of water is 1.15g/mL. The molarity of this solution is :

0.50M

1.78M

1.02M

2.05M