# What is the mole fraction of NaOH in an aqueous solution that contains 15.0% NaOH?

Jul 7, 2017

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#### Explanation:

15% NaOH by mass is 15g of NaOH in (100-15)g of solution.

No. Of moles of NaOH in solution = 0.65

No of moles of Water in solution = 4.72

Mole Fraction = $\left(\text{(Moles of Solvent)"/"(Moles Of Solute)+(Moles of Solvent)}\right)$
OR
$\left(\text{(Moles of Solvent)"/"Total Number Of Moles}\right)$

= 0.65 / 5.37
= 0.121

PS - Calculated this as per 'What is the mole fraction of NaOH in an aqueous solution that contains 15.0% NaOH by mass?'