Chemistry simulations

Let a reversible gas reaction settle into equilibrium, then disturb it — add a reactant, remove product, compress or expand the vessel, or heat or cool it — and watch the concentrations shift and resettle into a new equilibrium, with a visible colour change for the nitrogen dioxide reaction.

Pick a metal for each half-cell and set the ion concentrations, temperature and load, and see which electrode is the anode and which the cathode, the cell voltage from the Nernst equation, and electrons moving through the wire while ions move through the salt bridge. As the cell runs, the voltage falls and the two electrodes change in mass by different amounts.

Dial up acid concentration, temperature, and marble form and watch a gas syringe fill with CO2 — the marble is the limiting reagent, so every run ends at the same volume, only how fast it gets there changes. Traced against a dashed reference run.

Pick a balanced reaction and the amount of each reactant, and watch particles pair up in the equation's ratio until one reactant runs out. See the limiting reactant, the mass or gas volume of product made, and the excess left behind, and why moles, not grams, decide which runs out first.

Add strong base to an acid, strong or weak, and trace pH against volume — see the equivalence point's sharp jump and, for a weak acid, the buffer plateau where pH equals pKa at the half-equivalence point.