Chapter 6, Problem 64RQ

In the reaction between formic acid ${\text{(HCHO}}_{\text{2}}\text{)}$ and sodium hydroxide, water and sodium formate $\left({\text{NaCHO}}_{\text{2}}\right)$ are formed. To determine the heat of reaction, 75.0 mL of $\text{1}\text{.07 }M{\text{ HCHO}}_{\text{2}}$ was placed in a coffee-cup calorimeter at a temperature of $\text{22}\text{.4 °C}$, and 45.0 mL of 1.78 M NaOH, also at $\text{22}\text{.4 °C}$, was added. The mixture was stirred quickly with a thermometer, and its temperature rose to $\text{23}\text{.4 °C}$. Write the balanced chemical equation for the reaction. Calculate the heat of reaction in joules. Assume that the specific heats of all solutions are $\text{4}{\text{.18 J g}}^{\text{-1}}{\text{°C}}^{\text{-1}}$ and that all densities are $\text{1}{\text{.00 g mL}}^{\text{-1}}$. Calculate the heat of reaction per mole of acid $\left({\text{in units of kJ mol}}^{\text{-1}}\right)$.