The Correct Answer and Explanation is:
To solve this problem, one must use Table G, the Solubility Curves chart, from the Chemistry Regents Reference Table. This chart plots the solubility of various substances (in grams of solute per 100 grams of water) against temperature (in degrees Celsius). The state of a solution, whether it is saturated, unsaturated, or supersaturated, is determined by comparing the given amount of dissolved solute at a specific temperature to the solubility curve of that particular substance.
Here is the general method and definitions to identify each solution:
1. Unsaturated Solution: An unsaturated solution contains less solute than the maximum amount that can be dissolved in the solvent at that specific temperature. On the solubility graph, if you plot a point using the given temperature and mass of solute, this point will lie below the solubility curve for that substance. This means more solute can still be dissolved in the solution.
2. Saturated Solution: A saturated solution contains the maximum possible amount of dissolved solute at a given temperature. When you plot the point for a saturated solution, it will fall exactly on the solubility curve of the substance. At this point, the solution is in equilibrium; if any more solute is added, it will not dissolve.
3. Supersaturated Solution: A supersaturated solution contains more dissolved solute than is normally possible in a saturated solution at that temperature. This is an unstable state, usually achieved by dissolving a large amount of solute at a high temperature and then carefully cooling the solution. A point representing a supersaturated solution will lie above the solubility curve for that substance. These solutions are very unstable, and disturbing them can cause the excess solute to rapidly crystallize and precipitate out of the solution.
To identify any given solution, you would first locate the temperature on the x-axis and the mass of the solute on the y-axis. Find the point where these two values intersect on the graph. Then, locate the specific curve for the solute in question. By observing whether your plotted point is below, on, or above this curve, you can correctly identify the solution as unsaturated, saturated, or supersaturated, respectively.
