The solubility of MnSO4 · H2O in water at 20 °C is 70 g per 100 mL of water. (b) Given a solution of MnSO4 · H2O of unknown concentration, what experiment could you perform to determine whether the new solution is saturated, supersaturated, or unsaturated?

Name: Chemistry: The Central Science
Author: Brown
ISBN: 9780134414232

검증된 단계별 안내

Step 1: Understand the definitions of saturated, unsaturated, and supersaturated solutions. A saturated solution contains the maximum amount of solute that can dissolve at a given temperature. An unsaturated solution can dissolve more solute, while a supersaturated solution contains more solute than can typically dissolve at that temperature.

Step 2: Prepare a sample of the unknown MnSO4 · H2O solution. Ensure that the solution is at the same temperature as the given solubility data, which is 20 °C.

Step 3: Add a small amount of solid MnSO4 · H2O to the solution. Observe whether the added solute dissolves, remains undissolved, or causes crystallization.

Step 4: Analyze the observations: If the added solute dissolves, the solution is unsaturated. If the added solute does not dissolve, the solution is saturated. If crystallization occurs, the solution is supersaturated.

Step 5: Optionally, filter and dry any undissolved or crystallized MnSO4 · H2O to confirm the amount of solute present, comparing it to the known solubility to further verify the solution's status.

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Solubility

Solubility is the maximum amount of a solute that can dissolve in a solvent at a given temperature and pressure, resulting in a saturated solution. For MnSO4 · H2O, its solubility at 20 °C is 70 g per 100 mL of water, meaning that any solution containing more than this amount would be supersaturated, while less would be unsaturated.

Saturation Point

The saturation point is the stage at which a solution can no longer dissolve additional solute at a specific temperature. If a solution reaches this point, any added solute will remain undissolved, indicating that the solution is saturated. Understanding this concept is crucial for determining the state of the unknown solution.

Crystallization Test

A crystallization test involves cooling a solution or adding a small amount of solute to observe if crystals form. If crystals appear, the solution is likely supersaturated; if no crystals form and the solution remains clear, it is unsaturated. This test helps identify the concentration state of the unknown MnSO4 · H2O solution.