Question

The mole fraction of a solvent in aqueous solution of a solute is $0.8$. The molality (in mol $k{g}^{-1}$) of the aqueous solution is:

• A. $13.88\times {10}^{-1}$
• B. $13.88\times {10}^{-2}$
• C. $13.88$
• D. $13.88\times {10}^{-3}$

Answer 1

Answer: (C)

$13.88$

$X_{solvent}=0.8$

If $n_T=1$

$n_{Solvent}=0.8$

$n_{Solute}=0.2$

molality$=\frac{0.2}{0.8\times 18}\times 1000=13.88$