Chapter 9, Problem 9.12A

Interpretation Introduction

Interpretation:

The value of $\Delta H$ for ${\text{NH}}_{\text{4}}{\text{NO}}_{\text{3}}$ in kJ/mol needs to be determined.

Concept introduction:

The heat transferred to the surroundings is equal to the heat transferred by the reaction but in magnitude. The sign is opposite thus,

$q_{\text{reaction}}=-q_{\text{surroundings}}$

Here, solution is surrounding thus,

$q_{\text{surroundings}}=mc\Delta T$

Or,

$q_{\text{reaction}}=-mc\Delta T$

Here, m is mass, c is specific heat capacity and $\Delta T$ is the change in temperature.

The change in enthalpy is related to heat transfer as follows:

$\Delta H=\frac{q_{\text{reaction}}}{n}$

Here, n is the number of moles of a substance.