Question

How much water should you add?

5. The molality of hydrochloric acid, HCl, in an aqueous solution is 5.54 mol/kg.

What is the mole fraction of hydrochloric acid in the solution?

Answer 1

The mole fraction of hydrochloric acid in the solution is 0,09

Step-by-step explanation:

Mole fraction can it be for solvent, or solute. (In this case, HCl is solute)

Mole fraction solute = moles from solute / moles from solute + moles from solvent

We only have moles from solute which are 5,54 but as we have 1 kg of water we can know the moles from solvent.

Molar mass for water: 18 g/m

1 kg H2O = 1000 g

1000 g / |8 g/m = 55,5 moles from solvent

Mole fraction solute = moles from solute / moles from solute + moles from solvent

Mole fraction solute = 5,54 / 5,54 + 55,5 = 0,090