---
title: "A student uses a coffee-cup calorimeter to determine the molar enthalpy of dissolution of solid potassium nitrate, represented by the equation \\(\\text{KNO}_3\\text{(s)} \\rightarrow \\text{K}^+\\text{(aq)} + \\text{NO}_3^-\\text{(aq)}\\). The student obtains the following data.  | Measurement | Value | |—|—:| | Mass of \\(\\text{KNO}_3\\text{(s)}\\) | \\(10.1\\text{ g}\\) | | Mass of water | \\(89.9\\text{ g}\\) | | Initial temperature | \\(25.00^\\circ\\text{C}\\) | | Final temperature | \\(16.25^\\circ\\text{C}\\) |  Assume that the solution has a specific heat capacity of \\(4.00\\text{ J/(g}\\cdot^\\circ\\text{C)}\\), the calorimeter absorbs negligible heat, and the molar mass of \\(\\text{KNO}_3\\) is \\(101\\text{ g/mol}\\). What is the molar enthalpy of dissolution of \\(\\text{KNO}_3\\text{(s)}\\)?"
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url: "https://nerd-notes.com/ubq/119376/"
date_modified: "2026-08-19T12:40:04+00:00"
---

# A student uses a coffee-cup calorimeter to determine the molar enthalpy of dissolution of solid potassium nitrate, represented by the equation \(\text{KNO}_3\text{(s)} \rightarrow \text{K}^+\text{(aq)} + \text{NO}_3^-\text{(aq)}\). The student obtains the following data.

| Measurement | Value |
|—|—:|
| Mass of \(\text{KNO}_3\text{(s)}\) | \(10.1\text{ g}\) |
| Mass of water | \(89.9\text{ g}\) |
| Initial temperature | \(25.00^\circ\text{C}\) |
| Final temperature | \(16.25^\circ\text{C}\) |

Assume that the solution has a specific heat capacity of \(4.00\text{ J/(g}\cdot^\circ\text{C)}\), the calorimeter absorbs negligible heat, and the molar mass of \(\text{KNO}_3\) is \(101\text{ g/mol}\). What is the molar enthalpy of dissolution of \(\text{KNO}_3\text{(s)}\)?

A student uses a coffee-cup calorimeter to determine the molar enthalpy of dissolution of solid potassium nitrate, represented by the equation \(\text{KNO}_3\text{(s)} \rightarrow \text{K}^+\text{(aq)} + \text{NO}_3^-\text{(aq)}\). The student obtains the following data.

| Measurement | Value |
|---|---:|
| Mass of \(\text{KNO}_3\text{(s)}\) | \(10.1\text{ g}\) |
| Mass of water | \(89.9\text{ g}\) |
| Initial temperature | \(25.00^\circ\text{C}\) |
| Final temperature | \(16.25^\circ\text{C}\) |

Assume that the solution has a specific heat capacity of \(4.00\text{ J/(g}\cdot^\circ\text{C)}\), the calorimeter absorbs negligible heat, and the molar mass of \(\text{KNO}_3\) is \(101\text{ g/mol}\). What is the molar enthalpy of dissolution of \(\text{KNO}_3\text{(s)}\)?

- **A.** \(-35.0\text{ kJ/mol}\)
- **B.** \(+35.0\text{ kJ/mol}\)
- **C.** \(+350\text{ kJ/mol}\)
- **D.** \(+35{,}000\text{ kJ/mol}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119376/*