Chapter 9, Problem 9.83SP

Instant hot packs contain a solid and a pouch of water. When the pack is squeezed, the pouch breaks and the solid dissolves, increasing the temperature because of the exothermic reaction. The following reaction is used to make a hot pack:
$LiCI\left(s\right)\stackrel{H_{2}O}{\to }L{i}^{+}\left(aq\right)+C{I}^{-}\left(aq\right)$ $\Delta H=-36.\text{9 kJ}$
What is the final temperature in a squeezed hot pack that contains 25.0 g of LiCI dissolved in 125 mL of water?Assume a specific heat of 4.18 J/ (g.°C) for the solution, an initial temperature of 25.0 °C, and no heat transfer between the hot pack and the environment.