Question

48. Mole fraction of solute in aqueous solution of 30%
NaOH is
(1) 0.16
(2) 0.05
(3) 0.25
(4) 0.95​

Answer 1

Answer:

NaOH solution is prepared in water.

Molar mass of NaOH = 40 g

Mass of NaOH = 30 g

Molar mass of water = 18 g

Given mass of water = 70 g

Number of moles of NaOH = 3040 = 0.75 moles

Number of moles of H2O = 7018   = 3.88 moles

Mole fraction of NaOH = 0.75/0.75+3.88

=0.161

Answer 2

mass of naoh = 30g

mass of water in solution = 70g

molecular mass of naoh= 40g

molecular mass of water = 18g

no. of moles of naoh = 30/40= 0.75

no. of moles of water = 70/18= 3.88

mole fraction of solute=

0.75/0.75+3.88= 0.16