Manganese dioxide MnO sub 2 times s , Δ⁢H_f=−520.0kJ reacts with aluminum to form aluminum oxide Al sub 2 cap o sub 3 s , Δ⁢H_f=−1699.8kJ and manganese according to the equation. 3 MnO sub 2 s plus 4 Al s rightarrow 2 Al sub 2 cap o sub 3 g plus 3 Mn s What is the enthalpy of the reaction? Use Δ⁢H_rxn=∑(Δ⁢H_f_1p⁢r⁢o⁢d⁢u⁢c⁢t⁢s)−∑(Δ⁢H_f_1r⁢e⁢a⁢c⁢tan⁡t⁢s)