Rates of reaction

The gas volumes come from the model: each curve follows a smooth rule, so a real class would see some scatter. The gas is measured at room temperature and pressure.

The waits are shortened: each race lasts 3 minutes on the stopclock and takes about 15 seconds here.

The magnified view is a model, not to scale: 14 acid particles stand for the ordinary acid and 7 for the half-strength acid, and grey squares for the particles of marble. Only some of the collisions are shown.

With reduced motion, each step finishes at once.