Question

What is the mole fraction of solute and the molal concentration for an aqueous solution that is 10.0% NaOH by mass?

Answer 1

10 % NaOH by mass means that in 100 grams of solution 10 of those are NaOH.

Apply these formulas:

\(\sf molality=\dfrac{moles~of~solute}{kg~of~solution}\)

\(\sf mole~fraction~of~NaOH=\chi_{NaOH}=\dfrac{moles~of~NaOH}{moles~of~NaOH+moles~of~H_2O}\)