Question

Consider the following solubility graph. (a) At point \(A\), how many grams of the compound are dissolved in \(100 \mathrm{~g}\) of water? Is the solution saturated, unsaturated, or supersaturated? (b) At point \(B\), how many grams of the compound are dissolved in \(100 \mathrm{~g}\) of water? Is the solution saturated, unsaturated, or supersaturated? (c) How would you prepare a saturated solution at \(30^{\circ} \mathrm{C}^{2}\)

Short answer

Answer: The solubility curve in a solubility graph shows how the solubility of a compound in water changes with temperature. It can be used to identify the type of solution at a specific point by determining its position relative to the curve. If a point is on the curve, it represents a saturated solution, where the maximum amount of solute has been dissolved. If a point is above the curve, it represents a supersaturated solution, with more solute dissolved than typically possible. If a point is below the curve, it represents an unsaturated solution, where less solute is dissolved than the maximum possible amount at that temperature.

Step-by-step solution

Understanding solubility graphs

Solubility graphs show how the solubility (amount of solute that can be dissolved) of a compound in water changes with temperature. The graph is a curve that indicates the solubility at various temperatures. Points on the curve represent saturated solutions where the maximum amount of solute has been dissolved. Points above the curve represent supersaturated solutions, where more solute is dissolved than would typically be possible. Points below the curve represent unsaturated solutions, where less solute is dissolved than the maximum possible amount at that temperature.

Analyzing Point A

We're asked to find how many grams of compound are dissolved in 100g of water at point A, and determine if the solution is saturated, unsaturated, or supersaturated. To do this, locate point A on the solubility graph and read the corresponding solubility and temperature values. The solution type can be determined by whether the point is on, above, or below the curve.

Analyzing Point B

Similarly, we need to find how many grams of compound are dissolved in 100g of water at point B, and determine if the solution is saturated, unsaturated, or supersaturated. Locate point B on the solubility graph and read the corresponding solubility and temperature values. Determine the solution type by whether the point is on, above, or below the curve.

Preparing a saturated solution at \(30^{\circ} \mathrm{C}\)

To prepare a saturated solution at a specific temperature, we need to know the solubility of the compound at that temperature. Using the graph, find the solubility (in grams) of the compound in 100g of water at \(30^\circ \mathrm{C}\). Add this amount of solute to a beaker containing 100g of water at the desired temperature. Stir the mixture until the solute is completely dissolved and no more can dissolve, resulting in a saturated solution.