QUIZ: Thermochemistry Explain enthalpy (or heat) change Identify types and uses: Hrxn, Hfo, Hc Use Hrxn to determine if rxn is endo/exothermic Write thermochemical equation (two formats) Use Table I to determine stability of product More exo; lower energy product; higher stability Perform calculations using heat of reaction Basic Definition: Hrxn = Hproducts - Hreactants Calculate Hrxn given heats of formation of prod/reactants State and use Hess’s Law Calculate Hrxn from bond energies Define the term entropy and predict if a given reaction leads to an increase or decrease in entropy. Calcuate Srxn for a chemical change State the two driving forces in nature; define spontaneous process Use Gibbs free-energy change to predict if rxn is spontaneous Calcuate Grxn for a chemical change