Lesson: Hess Cycles Using Enthalpies of Formation Glencoe • Chemistry • Matter & Change • Chemistry • The Molecular Nature of Matter and Change • Eighth Edition • Chemistry 13e • AP Edition • Modern Chemistry • Glencoe Science • Chemistry • Matter and Change

In the early days of automobiles, illumination at night was provided by burning acetylene, . Though no longer used in headlamps, acetylene is still used as a source of light by some cave explorers. Acetylene can be prepared by the reaction of water with calcium carbide, : What is the standard enthalpy of the reaction?

The white pigment is prepared by the reaction of titanium tetrachloride, , with water vapor in the gas phase. How much heat is evolved in the production of exactly 1 mole of under standard state conditions?

Among the substances that react with oxygen and that have been considered as potential rocket fuels are diborane , produces and , methane , produces and , and hydrazine , produces and . On the basis of the heat released by 1.00 g of each substance in its reaction with oxygen, which of these compounds offers the best possibility as a rocket fuel?