A 9.40 g sample of KBr is dissolved in 105 g of ${\mathrm{H}}_2\mathrm{O}$ at ${23.6}^{\circ }\mathrm{C}$ in a coffee cup. Find the final temperature of this system. Assume that no heat is transferred to the cup or the surroundings.

Solution	Properties
Molar mass KBr	119 g/mol
$\mathrm{\Delta }{H}_{\text{ooln }}\mathrm{KBr}$	19.9 KJ/mol
$C_p$ solution	$4.184\mathrm{J}/{\mathrm{g}}^{\circ }\mathrm{C}$