Question

Mole fraction of NaOH if we mix 20gram of NaOH in 320gram of water

Answer 1

Given,

20 grams of NaOH is mixed with 320 grams of water to form a solution.

To find,

Mole fraction of NaOH

Main solution :

Molar mass of NaOH = (23 + 16 + 1 ) g = 40 g

Moles of NaOH in the given solution or mixture = given mass / molar mass = 20 /40 = 0.5 mole

Molar mass of water ( H2O ) = 2+16 = 18 g

Moles of water in this mixture or solution = given mass / molar mass = 320 / 18 = 17.78 ( approx ) mole.

Mole fraction of NaOH = moles of NaOH / moles of NaOH + moles of H2O = 0.5 / 0.5 + 17.78 = 0.5 / 18.28 = 0.027 ( approx ) { Answer }