Chapter 5, Problem 39QP

A quantity of $\text{2}\text{.00 }\times {\text{10}}^{\text{2}}\text{mL of 0}\text{.862 }M\text{ HCl}$ is mixed with $\text{2}\text{.00 }\times {\text{10}}^{\text{2}}\text{mL of 0}\text{.431 }M{\text{ Ba(OH)}}_2$ in a constant-pressure calorimeter of negligible heat capacity. The initial temperature of the $\text{HCl}$ and $\text{Ba}{\left(\text{OH}\right)}_{\text{2}}$ solutions is the same at $\text{20}\text{.48°C}$. For the process

${\text{H}}^{\text{+}}\left(aq\right)+{\text{OH}}^{\text{-}}\left(aq\right)\to {\text{H}}_{\text{2}}\text{O}\left(l\right)$

the heat of neutralization is $-56.2\text{ kJ/mol}$. What is the final temperature of the mixed solution? Assume the specific heat of the solution is the same as that for pure water.