Chapter 9, Problem 54E

In a coffee cup calorimeter, $\text{1}\text{.60 g}$ of ${\text{NH}}_{\text{4}}{\text{NO}}_{\text{3}}$ is mixed with $\text{75}\text{.0 g}$ of water at an initial temperature of $\text{25}\text{.00°C}$ . After dissolution of the salt, the final temperature of the calorimeter contents is $\text{23}\text{.34°C}$ . Assuming the solution has a heat capacity of $\text{4}{\text{.18 J °C}}^{\text{-1}}{\text{ g}}^{\text{-1}}$ and assuming no heat loss to the calorimeter, calculate the enthalpy change for the dissolution of ${\text{NH}}_{\text{4}}{\text{NO}}_{\text{3}}$ in units of $\text{kJ/mol}$ .