Bond Enthalpy Lab 2D: 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 a pannable, zoomable 2D scene — the formation of hydrogen chloride, the combustion of methane, and the Haber synthesis of ammonia — animating their reactant bonds breaking apart before their product bonds snap into place, while a synchronized reaction-coordinate energy diagram beneath the scene traces the system's energy from reactants, up through the fully-atomized intermediate, back down to the products. 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 and a curve you can watch it trace.