Question

What is the mole fraction of the solute in a 1.00 m aqueous
solution ? [2015 RS]
(a) 0.177 (b) 1.770
(c) 0.0354 (d) 0.0177

Answer 1

What is the mole fraction of the solute in a 1.00 m aqueous

solution ?

-it is given that molality = 1 m

- 1 molal aqueous solution means 1 kg of water contains 1 mol of solute

- No. of moles in 1 kg of water = 1000/18

                                                  = 55.55 moles

- mole fraction of solute = no. of moles of solute/ total no. of moles

                        X(solute) = 1/ (1 + 55.55)

                                        = 1/56.55  

                                        = 0.0177

- So the correct option is (d) 0.0177