Question

A solution is prepared by dissolving 15 g of urea in 250
g of water. The molality of the solution is :​

Answer 1

Answer:

1

Explanation:

molality = moles/kg

15g of urea = 15g of CH₄N₂O

Molar Mass of CH₄N₂O = 12 + 4 + 28 + 16 = 20 + 40 = 60 g

Formula for number of moles: $\frac{Mass \ in \ g}{Molar \ Mass}$

Number of moles = 15/60 = 1/4 moles

250 g = 1/4 Kg

Molality = (1/4) moles / (1/4) kg = 1

Answer 2

Answer:

1 m

Explanation:

mol of solute=15/60

=1/4

molality=mol of solute/mass of solvent

=(1/4)/(250/1000)

=1 m

The molality of the solution is : 1 m