Chapter 9, Problem 69E

Zinc metal reacts with hydrochloric acid according to the balanced equation:
$\text{Zn}\left(\text{s}\right)\text{ + 2 HCl}\left(\text{aq}\right)\to {\text{ ZnCl}}_{\text{2}}\left(\text{aq}\right){\text{+H}}_{\text{2}}\left(\text{g}\right)$
When 0.103 g of Zn(s) is combined with enough HCI to make 50.0 mL of solution in a coffee-cup calorimeter, all of the zinc reacts, raising the temperature of the solution from 22.5 °C to 23.7 °C. Find $\Delta {\text{H}}_{\text{rxn}}$ for this reaction as written. (Use 1.0 g/mL for the density of the solution and 4.18 J/g °C as the specific heat capacity.)