Question

12 g of a nonvolatile solute dissolved in 108 g of water produces the relative lowering of vapour pressure of 0.1. The molecular mass of the solute is ______.

विकल्प

• 80

• 60

• 20

• 40

Answer 1

12 g of a nonvolatile solute dissolved in 108 g of water produces the relative lowering of vapour pressure of 0.1. The molecular mass of the solute is 20.

Explanation:

${\displaystyle \frac{{\text{P}}^0-{\text{P}}_{\text{s}}}{{\text{P}}^0}=\frac{\text{n}}{\text{N}}=\frac{\text{w}}{\text{m}}\times \frac{\text{M}}{\text{W}}}$

0.1 = ${\displaystyle \frac{12}{\text{m}}\times \frac{18}{108}}$

m = ${\displaystyle \frac{12\times 18}{0.1\times 108}}$

m = 20