An aqueous solution contains 3.7 % nacl by mass.
calculate the molality of the solution.
calculate the mole fraction of the solution.

- Molality:

- Mole fraction:

Explanation:

Hello,

- Molality: in this case, the solution is formed by 3.7% by mass of sodium chloride and water, thereby, we assume we have 100 g of solution in order to find the mass of sodium chloride as shown below:

Hence, the moles of sodium chloride and kilograms of water are:

With which the molality results:

- Mole fraction: in this case, since we have previously computed the moles of sodium chloride, we now compute the moles of water as:

Thus, the mole fraction of sodium chloride is:

Best regards.

Answer : The molality of solution will be 0.62m and the mole fraction of solute is 0.10

Solution:

Molar mass of = 58.5g/mole

3.7% solution means 3.7 g of is present in 100 g of solution

Mass of water (solvent) =(100-3.7)=96.3 g

Molality : It is defined as the number of moles of solute present per kg of solvent.

Formula used :

where,

n = moles of solute

= weight of solvent in g

Now put all the given values in the formula of molality, we get

Therefore, the molality of solution will be 0.62 mole/kg.

Mole fraction of solute(NaCl)=

Moles of solute(NaCl)= 0.6

Moles of solvent (water)=

Total moles =0.6+5.35=5.95

Mole fraction of solute(NaCl)=