Question

The density of 20% (w/w) aqueous NaOH
solution is 1.20 g.mL-1. What is the mole
fraction of water ?(molar mass of NaOH
40g.mol-')
1) 0.95 2) 0.90 3) 0.97 4) 0.94​

Answer 1

Explanation:

moles of water =

18

900

=50

According to Raoult's law, mole fraction of solvent =

P

solvent

O

P

solvent

=

30

24

=

5

4

=0.8