Passage III

The solubility of a substance is typically defined as the maximum mass, in grams (g), of the substance (the solute) that will stay dissolved in 100 g of a solvent (such as water). The solubility of a substance generally varies as the temperature of the solvent changes. Figure 1 shows, for each of 5 substances, how solubility in water varies with temperature.

Figure 2 shows, for 3 temperatures (25°C, 40°C, and 60°C), how the solubility of sucrose varies as the percent by mass of water in solvent mixtures of water and ethanol varies.

Figure 2 adapted from A. M. Peres and E. A. Macedo, "Phase Equilibria of D-glucose and Sucrose in Mixed Solvent Mixtures: Comparison of UNIQUAC-based Models." ©1997 by Elsevier Science Ltd.

18. Based on Figure 2, does the solubility of sucrose generally increase as the percent ethanol in the solvent mixture increases, and does the solubility of sucrose generally increase as the temperature of the solvent increases?

percent ethanol increases ---- temperature increases

Answer and Explanation

Your Answer is

Correct Answer is H

Explanation

According to Figure 2, it can be seen that the more water, the less ethanol (the larger the horizontal axis), the greater the solubility, and the two are inversely proportional; under the same water percent, the higher the temperature, the greater the solubility, and the two are proportional, so Choose H