Question

The density of a solution prepared by dissolving 120 g of urea (Molar mass = 60 g/mol) in 500 g of water is 1.15 g/ml. The molarity of this solution is

Answer 1

Answer:

1234526gm mol solutions please

Answer 2

Explanation:

Molarity is defined as the number of moles of solute dissolved in per litre of solution.

Molarity, M=

V

n

n=number of moles of solute=mass/molar mass

V=volume of solution

mass of urea (NH

2

CONH

2

)=120g

Molar mass of urea= 60g/mol

Mass of water=1000g

Density of solution. ρ=1.15 g/mL

n=120/60=2mol

m

solution

=m

solute

+m

solvent

(∵ Law of conservation of mass)

ρ

solution

×V

solution

=120+1000 (using m=ρ.V)

1.15×V

solution

=1120

V

solution

=974mL=0.974L

thus M=

V

n

=

0.974

2

=2.05M

Molarity of the solution is 2.05M