Question

Mole fraction of a solute in benzene is 0.2 then find the molality of solute

Answer 1

Answer:

0.2=2/10;

na=2;nb=8;w=8×18=144

m=2/144=1/72

Answer 2

$\large\underline\mathrm\red{Given:-}$

• Mole fraction of solute = 0.2

$\large\underline\mathrm\red{Solution}$

Let molarity of solution = x

Moles of solute in 1000 g benzene

$\implies$1000/78

$\implies$12.82

Mole fraction of solute = x / x + 12.82

$\large\underline\mathrm\red{Given \: mole \: fraction \: of \: solute \: = \: 0.2}$

$\implies$0.2 (x + 12.82) = x

$\implies$0.2x + 2.564 = x

$\implies$2.564 = x - 0.2x

$\implies$x = 2.564/0.8

$\implies$x = 3.2

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