This simulation models the classic "elephant toothpaste" demonstration: the rapid catalytic decomposition of hydrogen peroxide into water and oxygen gas, 2 H₂O₂ → 2 H₂O + O₂. Adding a catalyst — potassium iodide or catalase from yeast — collapses the reaction's activation energy barrier so peroxide that would otherwise take days to break down does so in seconds, releasing heat and a burst of oxygen. Dish soap in the flask traps that oxygen as a stable foam instead of letting it fizz away, and with nowhere to expand but up, the foam erupts out of the flask's narrow neck. Adjust the peroxide concentration, catalyst amount and soap level to see how each independently controls the total foam produced, how fast the eruption happens, and how dense and stable the foam column is — then add the catalyst and watch it erupt.