The lab runs the balanced reaction 2 H₂ + O₂ → 2 H₂O one packet at a time. You choose how many hydrogen and oxygen molecules to start with and watch each packet take two H₂ and one O₂ and return two water molecules, until a reactant runs out.
• A hydrogen reactant shelf, an oxygen reactant shelf, an atom rearrangement window and a water product shelf. • Sliders for initial H₂ molecules (0 to 8) and O₂ molecules (0 to 4) and a toggle for explanatory particles. • Readouts: unreacted H₂, unreacted O₂, formed H₂O, total hydrogen atoms, total oxygen atoms and completed reaction packets. • Experiments: oxygen limiting ends with two water molecules and six unused H₂; hydrogen limiting ends with two water molecules and three unused O₂.
The maximum extent is ξ_max = min(floor(N_H₂/2), N_O₂). Then N_H₂ = N_H₂,0 − 2ξ, N_O₂ = N_O₂,0 − ξ and N_H₂O = 2ξ. The atom totals stay constant throughout, because only connectivity changes.
This is discrete stoichiometric bookkeeping, not a reaction mechanism, an ignition model or a kinetic rate law. Each illustrative packet takes four animation seconds. Fractional conversion is shown only as a rearrangement transition; completed molecule counts are integers.
No. Bond connectivity changes, but each element's atom count is conserved. The hydrogen and oxygen atom totals in the readouts never change.
Two. The balanced ratio is two H₂ to one O₂, so four H₂ use two O₂ and produce four H₂O.
The reactant that runs out first. The simulator uses ξ_max = min(floor(N_H₂/2), N_O₂), and the leftover of the other reactant appears as unreacted molecules.
No. It has no kinetics or ignition. It only counts what happens once packets complete.