Question

A mixture contains 80% of NaOH and 20% H2O by weight, what is the mole fraction of NaOH?

(a) 0.24

(b) 0.42

(c) 0.64

(d) 0.78

This question was posed to me in exam.

I want to ask this question from Mole Fraction and Mass(Weight) Fraction in portion Moles, Density & Concentration of Basic Chemical Engineering

Answer 1

Right option is (c) 0.64

Best explanation: Mole fraction of HCl = (80/40)[(80/40) + (20/18)] = 0.64.