Bond Enthalpy Lab: Reaction Heat from Bond Energies

Every chemical reaction is, at its core, a bookkeeping problem in bond energy: old bonds break, absorbing energy, and new bonds form, releasing it. This simulator renders three real reactions in 3D — the formation of hydrogen chloride, the combustion of methane, and the Haber synthesis of ammonia — and animates their reactant bonds breaking apart before their product bonds snap into place, tallying the energy absorbed and released against tabulated average bond dissociation energies in real time. The resulting ΔH read-out shows directly why combustion is sharply exothermic while ammonia synthesis is only mildly so, grounding the abstract enthalpy formula ΔH = ΣD(broken) − ΣD(formed) in a mechanic you can watch happen.