In the aqueous solution of sulphuric acid themole fraction of water is

1.	In the aqueous solution of sulphuric acid themole fraction of water is 0.85. The molality ofthe solution is(A) 8.9 m(C) 9.8 m(B) 0.19 m(D) 15 m
Answer» The relationship between mole fraction and molality is given as m=1000 X xB/(1-XB)X Molecular weoght of solvent The tricky part in this question is observing which is solute and solvent. Mole fraction of water is 0.85 which means it is not the solute but it is the SOLVENT. We know that mole fraction of solute+mole fraction of solvent=1 Therefore, xB=0.15 Substitute it in given equation, 1000(0.15)/(0.85)(18) Which is equal to 9.8

In the aqueous solution of sulphuric acid themole fraction of water is 0.85. The molality ofthe solution is(A) 8.9 m(C) 9.8 m(B) 0.19 m(D) 15 m

Answer»

The relationship between mole fraction and molality is given as

m=1000 X xB/(1-XB)X Molecular weoght of solvent

The tricky part in this question is observing which is solute and solvent.

Mole fraction of water is 0.85 which means it is not the solute but it is the SOLVENT.

We know that mole fraction of solute+mole fraction of solvent=1

Therefore, xB=0.15

Substitute it in given equation,

1000(0.15)/(0.85)(18)

Which is equal to 9.8