Given the following: Measurement Reaction 1 (Mg + HCl)
Mass of HCl (g) 100.50
Mass of solid (g) 0.20
Total mass of reactants, m (g) (add the masses above) 100.70
Initial Temperature (°C) 22.5
Temperature furthest from initial temperature(°C) 31.3
∆T(°C) Subtract the two temperatures above) 8.8

Given Reaction 1: Mg(s) + 2HCl(aq) ⟶ MgCl2(aq) + H2(g)

What is the ∆H (kJ/mol)?