Bondenergyduringareaction - Study guides, Class notes & Summaries

Enthalpy Changes The total chemical energy inside a substance is called the enthalpy (or heat content) When chemical reactions take place, changes in chemical energy take place and therefore the enthalpy changes An enthalpy change is represented by the symbol ΔH (Δ= change; H = enthalpy) An enthalpy change can be positive or negative Exothermic reactions A reaction is exothermic when the products have less energy than the reactants Heat energy is given off by the reaction to the surroun...