The solubilites of different solutes in a given solvent can be compared by

Analysis

The question asks for the standard scientific method used to compare the solubilities of different substances (solutes) in a specific solvent at varying temperatures.

Concept Explanation

A solubility curve is a graphical representation of how the solubility of a solute changes with temperature. The y-axis typically represents the solubility (usually in grams per 100g of solvent), and the x-axis represents the temperature (in degrees Celsius).

To compare two or more different solutes effectively, you must be able to see their solubility values side-by-side at the same temperature points. If you plot them on separate graphs (separate axes), you lose the visual reference needed to see which solute is more or less soluble than the other at a specific temperature.

Step-by-Step Solution

1. Understand the Goal: We want to compare the solubility of Substance A vs. Substance B.
2. Standardize the Variables: For a valid comparison, both substances must be measured against the same independent variable (temperature) and the same dependent variable (solubility).
3. Graphical Representation: By plotting both curves on the same set of axes (same x-axis for temperature and same y-axis for solubility), the curves will intersect or run parallel. This allows you to immediately identify: • Which substance is more soluble at a specific temperature. • How the rate of solubility change differs between the substances.
4. Evaluate Options: • Option A is incorrect because separate axes make visual comparison difficult. • Option B is correct because it provides a common reference frame for both solutes. • Options C and D are mathematically incorrect and do not follow standard graphing conventions for solubility.

Conclusion

Exam Tip: When you see a solubility curve question in your JAMB exam, remember that the "steeper" the curve, the more sensitive the solubility of that substance is to temperature changes. If two curves intersect, that point of intersection represents the temperature at which both substances have the exact same solubility.