Molality of a solution in aqueous medium is $0.8$ . Calculate its mole fraction and the percentage by mass of solute if molar mass of solute is $60.$

0.014,

4.8

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0.014,

5

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0.1,

4.8

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0.4,

8

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Solution

The correct option is A $0.014,$ $4.8$ %
We know that,

$m = \frac{x_{B} \times 1000}{(1 - x_{b}) \times m_{A}}$

Where $x_{B}$ = mole fraction of the solute.

And $m_{A}$ = molar mass of the solvent

0.8 = $\frac{x_{B} \times 1000}{(1 - x_{b}) \times 18}$

$x_{B} = 0.014$

Let $w_{B}$ = x gram and $w_{A} = 100$ gram

$m = \frac{w_{B} \times 1000}{m_{B} \times w_{A}}$

$0.8 = \frac{x \times 1000}{60 \times 1000}$

$x = 4.8$ %

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Molality of a solution in aqueous medium is 0.8. Calculate its mole fraction and the percentage by mass of solute if molar mass of solute is 60.

The correct option is A 0.014, 4.8%We know that, m=xB×1000(1−xb)×mA Where xB = mole fraction of the solute. And mA = molar mass of the solvent 0.8 = xB×1000(1−xb)×18 xB=0.014 Let wB = x gram and wA=100 gram m=wB×1000mB×wA 0.8=x×100060×1000 x=4.8%

Molality of a solution in aqueous medium is $0.8$ . Calculate its mole fraction and the percentage by mass of solute if molar mass of solute is $60.$