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Ch.13 - Properties of Solutions
All textbooksBrown 14th EditionCh.13 - Properties of SolutionsProblem 24
Chapter 13, Problem 24

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?

Verified step by step guidance
1
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.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

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.
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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.
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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.
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Related Practice
Textbook Question

Two nonpolar organic liquids, hexane (C6H14) and heptane (C7H16), are mixed. (b) Hexane and heptane are miscible with each other in all proportions. In making a solution of them, is the entropy of the system increased, decreased, or close to zero, compared to the separate pure liquids?

Textbook Question

KBr is relatively soluble in water, yet its enthalpy of solution is + 19.8 kJ/mol. Which of the following statements provides the best explanation for this behavior? (a) Potassium salts are always soluble in water. (b) The entropy of mixing must be unfavorable. (c) The enthalpy of mixing must be small compared to the enthalpies for breaking up water–water interactions and K–Br ionic interactions. (d) KBr has a high molar mass compared to other salts like NaCl.

Textbook Question

By referring to Figure 13.15, determine whether the addition of 40.0 g of each of the following ionic solids to 100 g of water at 40 °C will lead to a saturated solution:(c) K2Cr2O7

Textbook Question

By referring to Figure 13.15, determine whether the addition of 40.0 g of each of the following ionic solids to 100 g of water at 40 °C will lead to a saturated solution: (d) Pb(NO3)2.

Textbook Question

By referring to Figure 13.15, determine the mass of each of the following salts required to form a saturated solution in 250 g of water at 30 °C: (b) Pb(NO3)2,