Passage I

The freezing point of an aqueous solution (Tf), in °C, can be calculated using the equation

Tf = −1.86 × m × i

where m is the concentration of the solute in moles of solute per kilogram of H2O (mol/kg H2O) and i is the average number of particles produced by 1 formula unit of the solute when the formula unit dissolves in H2O. The theoretical i value of a solute is the total number of particles produced when 1 formula unit of the solute dissolves in H2O. Table 1 gives, for 4 ionic compounds, the chemical formula and the theoretical i value. Table 2 shows how the observed i value at 25°C for these compounds changes with solute concentration.

Table 2 adapted from B. A. Kunkel, “Comments on ‘A Generalized Equation for the Solution Effect in Droplet Growth.’ ” ©1969 by American Meteorological Society.

6. Sucrose (C12H22O11) is a molecular compound and remains intact when it dissolves in water. Based on this information and the passage, would the theoretical i value for C12H22O11 more likely be less than that of KCl or greater than that of KCl ?

Answer and Explanation

Your Answer is

Correct Answer is F

Explanation

The C12H22O11 described in the title stem is complete when dissolved in water, that is, it will not In the case of decomposing into multiple particles, according to the definition of i value in the article, the theoretical i value of C12H22O11 is obtained is 1. According to Table 1, the theoretical i value of KCl is 2, so choose F for this question