Question

If given the mole fraction of water in an aqueous sucrose (C12H22O11) solution and asked to calculate the molality of the solution at the same temperature, what additional information would you need to be given in order to complete the problem?

Answer 1

Answer:

No additional information is required in order to calculate the molality of the solution.

Explanation:

Mole fraction of water = $\chi_1$

Mole fraction of sucrose = $\chi_2$

$\chi_1+\chi_2=1$

From the given mole fraction of water mole fraction of sucrose can be determined.

And from both values of mole fraction moles of water and sucrose can also be calculated.

$\chi_1=\frac{n_1}{n_1+n_2}$

$\chi_2=\frac{n_2}{n_1+n_2}$

After calculating the moles of water convert them into mass of water in grams and then change that into kilograms say that be M'.

Finally we can determine the molality of solution ;

$Molality=\frac{\text{Moles of compound}}{\text{mass of solvent (kg)}}$

Molality of the sucrose solution ;

$m=\frac{n_1}{M'}$

From this we can conclude that no additional information is required in order to calculate the molality of the solution.