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title: "A student investigates the thermodynamics of dissolving salts by adding \\(0.050\\text{ mol}\\) of four different anhydrous ionic compounds to separate, insulated calorimeters each containing \\(100.0\\text{ g}\\) of distilled water. In each trial, the mixture is stirred until the salt completely dissolves, and the temperature is recorded. The data are shown in the table below.  | Salt | Initial temperature (\\(^\\circ\\text{C}\\)) | Final temperature (\\(^\\circ\\text{C}\\)) | | :— | :— | :— | | \\(\\text{LiCl}(s)\\) | \\(22.0\\) | \\(26.4\\) | | \\(\\text{NH}_4\\text{NO}_3(s)\\) | \\(22.0\\) | \\(18.3\\) | | \\(\\text{CaCl}_2(s)\\) | \\(22.0\\) | \\(31.8\\) | | \\(\\text{KCl}(s)\\) | \\(22.0\\) | \\(19.9\\) |  Which of the following claims about the dissolution process is best supported by the data?"
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url: "https://nerd-notes.com/ubq/123752/"
date_modified: "2026-09-28T12:29:21+00:00"
---

# A student investigates the thermodynamics of dissolving salts by adding \(0.050\text{ mol}\) of four different anhydrous ionic compounds to separate, insulated calorimeters each containing \(100.0\text{ g}\) of distilled water. In each trial, the mixture is stirred until the salt completely dissolves, and the temperature is recorded. The data are shown in the table below.

| Salt | Initial temperature (\(^\circ\text{C}\)) | Final temperature (\(^\circ\text{C}\)) |
| :— | :— | :— |
| \(\text{LiCl}(s)\) | \(22.0\) | \(26.4\) |
| \(\text{NH}_4\text{NO}_3(s)\) | \(22.0\) | \(18.3\) |
| \(\text{CaCl}_2(s)\) | \(22.0\) | \(31.8\) |
| \(\text{KCl}(s)\) | \(22.0\) | \(19.9\) |

Which of the following claims about the dissolution process is best supported by the data?

A student investigates the thermodynamics of dissolving salts by adding \(0.050\text{ mol}\) of four different anhydrous ionic compounds to separate, insulated calorimeters each containing \(100.0\text{ g}\) of distilled water. In each trial, the mixture is stirred until the salt completely dissolves, and the temperature is recorded. The data are shown in the table below.

| Salt | Initial temperature (\(^\circ\text{C}\)) | Final temperature (\(^\circ\text{C}\)) |
| :--- | :--- | :--- |
| \(\text{LiCl}(s)\) | \(22.0\) | \(26.4\) |
| \(\text{NH}_4\text{NO}_3(s)\) | \(22.0\) | \(18.3\) |
| \(\text{CaCl}_2(s)\) | \(22.0\) | \(31.8\) |
| \(\text{KCl}(s)\) | \(22.0\) | \(19.9\) |

Which of the following claims about the dissolution process is best supported by the data?

- **A.** The dissolution of \(\text{CaCl}_2(s)\) is endothermic with \(\Delta H_{\text{soln}} > 0\), because thermal energy was released into the solution, increasing its temperature.
- **B.** The dissolution of \(\text{KCl}(s)\) is exothermic with \(\Delta H_{\text{soln}} < 0\), because thermal energy was transferred to the salt, decreasing the temperature of the solution.
- **C.** The dissolution of \(\text{NH}_4\text{NO}_3(s)\) is endothermic with \(\Delta H_{\text{soln}} > 0\), because thermal energy was absorbed from the water by the system, decreasing the temperature of the solution.
- **D.** The dissolution of \(\text{LiCl}(s)\) is exothermic with \(\Delta H_{\text{soln}} > 0\), because thermal energy was transferred from the system to the water, increasing the temperature of the solution.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/123752/*