The reaction that was on the screen when you started and its derivative demonstrate that the change in enthalpy for a reaction, Delta H, is an extensive property. Using this property, calculate the change in enthalpy for Reaction 2. Reaction 1: C3H8 (g) +5 O2(g)==> CO2(g) + 4 H2O(g), Delta H1 = -2043 kJ Reaction 2: 4C3H8 (g) +20O2(g) ==>12CO2(g) + 16H2O(g), Delta H2 = ?