Question

In the aqueous solution of sulphuric acid the mole fraction of water is 0.85. The molality of the solution is-​

Answer 1

Answer:

Explanation:

Mole fraction of solution = solute + solvent = 1.

Here, Mole fraction of water is 0.85 so mole fraction of sulphuric acid will be (1-0.85) = 0.15.

Hence each mole of the solution, 0.15 mole of sulphuric acid is dissolved .

So mass of solvent (water) is ,

For 1 mole of water H2O = 18 gm.

So, 0.85 mole of water = 18 x 0.85 = 15.3 gm =0.0153 Kg.

Thus, Molality (m) = no. of moles of solute (Sulphuric acid)/ mass of solvent in Kg.

Hence, Molality of the solution (m) = 0.15 / 0.0153 = 9.8 m=> approx(10).