To determine the enthalpy change for this reaction, 0.158 g of Mg metal is combined with enough HCl to make 100.0 mL of solution in a coffee-cup calorimeter of negligible heat capacity. The HCl is sufficiently concentrated so that the Mg completely reacts. The temperature of the solution rises from 25.6oC to 32.8oC as a result of the reaction. Find the ?Horxn (in kJ/mol) for the reaction as written. Use 1.00 g/mL as the solution density and the specific heat capacity of the solution = 4.181 J/g oC.