Manganese dioxide (mno2(s), hf = –520. 0 kj) reacts with aluminum to form aluminum oxide (ai2o3(s), hf = –1699. 8 kj/mol) and manganese according to the equation below. What is the enthalpy of the reaction? use. –1,839. 6 kj –1,179. 8 kj 1,179. 8 kj 1,839. 6 kj.