When $50\mathrm{.}0mL$ of $1\mathrm{.}0mo\frac{l}{L}$ hydrochloric acid is neutralized completely by $75\mathrm{.}0mL$ of $1\mathrm{.}0mo\frac{l}{L}$ sodium hydroxide in a coffee$-$cup calorimeter, the temperature of the total solution changes from $20\mathrm{.}2C$ to $25\mathrm{.}6C.$ Determine the quantity of energy transferred, $q,$ and state whether the reaction was endothermic or exothermic. $[$ans: $2800,,$ exothermic$]$