Question

Mole fraction of solute in aqueous solution of 30% NaOH!!!! Calculate fast.. :-)

Answer 1

Hello!

• Mass of NaOH = $\bf{30\: g}$
• Molar mass of NaOH = $\bf{40 \:g}$
• Molar mass of Water = $\bf{18 \:g}$

$\underline{\sf Now}$ :

♦ Number of moles of H₂O = $\dfrac{\sf 70}{\sf 18}$ = $\boxed{\sf 3.88 \:moles}$

♦ Number of moles of NaOH = $\dfrac{\sf 30}{\sf 40}$ = $\boxed{\sf 0.75\: moles}$

Then,

$\bf{Mole \:fraction\: of\: NaOH}$ = $\dfrac{\sf 0.75}{\sf 0.75 + 3.88} = \boxed{\boxed{\sf 0.161}}$

Cheers!