Question

calculate molality of aq solution of unknown solute if mole fraction of water in the solution is 0.60​

Answer 1

Answer:

0.037

Explanation:

In chemistry, the mole fraction or molar fraction (x) is defined as the amount of a constituent (expressed in moles), ni divided by the total amount of all constituents in a mixture (also expressed in moles).

The sum of all the mole fractions is equal to 1 ,

if mole fraction of water is 0.60, the mole fraction of the solute is 0.40

mole fraction x of the unknown solute, x= 0.4

molar mass Mo of the solvent H2O, Mo = 18

molality b of the solute? (see attached formula)

b = x / Mo(1-x) = 0.4 / (18 * 0.6) = 0.4 / 10.8 = 0.037  

Answer 2

Answer:

Explanation:n1/n1+n2 =0.60

: n2/n1+n2 =0.40

Or n2/n1 =0.4/0.6 = 2/3

n2/1000/18 = 2/3

n2 =37.03moles

hence,molality =37.03 Moles/kg