Chapter 12, Problem 82RQ

Interpretation Introduction

Interpretation:

To make sugar candy, a concentrated sucrose solution is boiled until the temperature reaches 272 $°\mathrm{F}.\mathrm{ }$ The molality and mole fraction of sucrose of the given mixture are to be determined.

Concept Information:

Molality of a solution is defined as the number of moles of solute in one kilogram (kg) of solvent. It is denoted by m.

Mole fraction of a component is defined as the number of moles of a solute divided by the total number of moles present in the solution. The mole fraction of all the components present in the solution, when added, makes it unity. It is given by equation: $$

$\left(X_{solute}\right)=\left(\frac{n_A}{n_A+n_b}\right)$

The amount by which the boiling point is raised is called the boiling point elevation, ∆T_b. Its relationship with molality is given as ∆T_b = K_bm, where K_b is molal boiling point elevation constant.