Question

What is the mole fraction of solute in a 3.19 m aqueous solution?

Answer 1

Molality= mol/ Kg

if we assume that we have 1 kg of water, we have 3.19 moles of solute. 

the formula for mole fraction --> mole fraction= mol of solule/ mol of solution

1) if we have 1 kg of water which is same as 1000 grams of water. 

2) we need to convert grams to moles using the molar mass of water 

molar mass of H₂O= (2 x 1.01) + 16.0 = 18.02 g/mol

1000 g (1 mol/ 18.02 grams)= 55.5 mol

3) mole of solution= 55.5 moles + 3.19 moles= 58.7 moles of solution

4) mole fraction= 3.19 / 58.7= 0.0543