Given the task definition and input, reply with output. Given a scientific passage and an answer, generate a question for the given answer.

Passage: 2Al(s) + Fe2O3(s) → 2Fe(s) + Al2O3(s) + heat to indicate that heat is one of the products. Chemical equations in which heat is shown as either a reactant or a product are called thermochemical equations. In this reaction, the system consists of aluminum, iron, and oxygen atoms; everything else, including the container, makes up the surroundings. During the reaction, so much heat is produced that the iron liquefies. Eventually, the system cools; the iron solidifies as heat is transferred to the surroundings. A process in which heat (q) is transferred from a system to its surroundings is described as exothermic. By convention, q < 0 for an exothermic reaction. Answer: thermochemical equations

Chemical equations in which heat is shown as either a reactant or a product are called what?