Answer:

The mole fraction of SOLVENT is 0.95

Explanation:

We are given:

Molality of NaOH solution = 3m

This means that 3 moles of NaOH is PRESENT in 1 kg (1000 g) of solvent.

As, the solution is aqueous in nature which means that the solvent is water.

Calculating the moles of water in the solution, by using the equation:

\text{NUMBER of moles}=\frac{\text{Given mass}}{\text{Molar mass}}Number of moles=

Molar mass

Given mass

Given mass of water = 1000 g

Molar mass of water = 18 g/mol

PUTTING values in above equation , we get:

\text{Moles of water}=\frac{1000g}{18g/mol}=55.55molMoles of water=

18g/mol

1000g

=55.55mol

To calculate the mole fraction of solvent, we use the equation:

\chi_{water}=\frac{n_{water}}{n_{water}+n_{NaOH}}χ

water

=

n

water

+n

NaOH

n

water

We are given:

\begin{lgathered}n_{water}=55.55mol\\n_{NaOH}=3mol\end{lgathered}

n

water

=55.55mol

n

NaOH

=3mol

Putting values in above equation, we get:

\chi_{water}=\frac{55.55}{55.55+3}=0.95χ

water

=

55.55+3

55.55

=0.95

Hence, the mole fraction of solvent is 0.95