---
title: "A student dissolves a sample of solid ammonium nitrate, \\(\\text{NH}_4\\text{NO}_3\\text{(s)}\\), in distilled water at \\(298\\text{ K}\\) according to the equation below.  \\[ \\text{NH}_4\\text{NO}_3\\text{(s)} \\rightleftharpoons \\text{NH}_4^+\\text{(aq)} + \\text{NO}_3^-\\text{(aq)} \\]  As the solid dissolves, the temperature of the mixture decreases from \\(25.0^\\circ\\text{C}\\) to \\(18.4^\\circ\\text{C}\\). Which of the following correctly identifies the signs of \\(\\Delta H_{\\text{soln}}^\\circ\\) and \\(\\Delta S_{\\text{soln}}^\\circ\\), and predicts the effect of increasing temperature on the solubility of \\(\\text{NH}_4\\text{NO}_3\\text{(s)}\\)?"
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url: "https://nerd-notes.com/ubq/123921/"
date_modified: "2026-09-28T12:32:12+00:00"
---

# A student dissolves a sample of solid ammonium nitrate, \(\text{NH}_4\text{NO}_3\text{(s)}\), in distilled water at \(298\text{ K}\) according to the equation below.

\[ \text{NH}_4\text{NO}_3\text{(s)} \rightleftharpoons \text{NH}_4^+\text{(aq)} + \text{NO}_3^-\text{(aq)} \]

As the solid dissolves, the temperature of the mixture decreases from \(25.0^\circ\text{C}\) to \(18.4^\circ\text{C}\). Which of the following correctly identifies the signs of \(\Delta H_{\text{soln}}^\circ\) and \(\Delta S_{\text{soln}}^\circ\), and predicts the effect of increasing temperature on the solubility of \(\text{NH}_4\text{NO}_3\text{(s)}\)?

A student dissolves a sample of solid ammonium nitrate, \(\text{NH}_4\text{NO}_3\text{(s)}\), in distilled water at \(298\text{ K}\) according to the equation below.

\[ \text{NH}_4\text{NO}_3\text{(s)} \rightleftharpoons \text{NH}_4^+\text{(aq)} + \text{NO}_3^-\text{(aq)} \]

As the solid dissolves, the temperature of the mixture decreases from \(25.0^\circ\text{C}\) to \(18.4^\circ\text{C}\). Which of the following correctly identifies the signs of \(\Delta H_{\text{soln}}^\circ\) and \(\Delta S_{\text{soln}}^\circ\), and predicts the effect of increasing temperature on the solubility of \(\text{NH}_4\text{NO}_3\text{(s)}\)?

- **A.** \(\Delta H_{\text{soln}}^\circ < 0\) and \(\Delta S_{\text{soln}}^\circ < 0\) | Solubility decreases
- **B.** \(\Delta H_{\text{soln}}^\circ < 0\) and \(\Delta S_{\text{soln}}^\circ > 0\) | Solubility increases
- **C.** \(\Delta H_{\text{soln}}^\circ > 0\) and \(\Delta S_{\text{soln}}^\circ < 0\) | Solubility increases
- **D.** \(\Delta H_{\text{soln}}^\circ > 0\) and \(\Delta S_{\text{soln}}^\circ > 0\) | Solubility increases

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/123921/*