Chapter 5, Problem 114AP

A 3.52-g sample of ammonium nitrate ${\text{(NH}}_{\text{4}}{\text{NO}}_{\text{3}}\text{)}$ was added to 80.0 mL of water in a constant-pressure calorimeter of negligible heat capacity. As a result, the temperature of the solution decreased from 21.6°C to 18.1°C. Calculate the heat of solution $\text{(}\Delta H_{\text{soin}})$ in kJ/mol:

${\text{NH}}_4{\text{NO}}_{\text{3}}\text{(}s\text{)}\underset{}{\to }{\text{NH}}_{\text{4}}^{\text{+}}\text{(}aq{\text{)+NO}}_{\text{3}}^{\text{-}}\text{(}aq\text{)}$

Assume the specific heat of the solution is the same as that of water.