Question

100 g solution of urea in water has 10 g of urea
(molar mass = 60 g mot). The molality of solution is
(1) 3.12 m
(2) 1.85 m
(3) 1.11 m
(4) 2.5 m
​

Answer 1

Answer:

As we know that , Molality = Wb x 1000

GMMb Wa

here , Wb = 10g

GMMb = 60g

Wa = 90g

Therefore , Molality = 10 x 1000

60 90

or , Molality = 100

54

or ,Molality = 1.852m

Therefore , option (2)1.85m

Answer 2

Answer:

2) 1.85

Explanation:

Mass of Solute given = 10g

Mass of Solvent = 100g - 10g = 90g

no. of moles of solute=10g/60=1/6

mass of Solvent in kg= 90/1000 = 0.09

molality = no. of moles of solute/ mass of Solvent in kg

= 1/6 ÷ 0.09= 1.85

hope this helps you