Measuring gas volume over time – average and instantaneous rate of reaction

ChemistryKinetics & EquilibriumAges 15–16

Virtual experiment: add CaCO₃ (lumps or powder) or Zn to 50 mL of HCl solution; the CO₂ or H₂ produced pushes out the plunger of a gas syringe while a stopwatch runs and the V(t) graph is plotted. Students drag two time markers to find the average rate (secant) and the instantaneous rate (tangent), then change concentration, temperature and surface area and compare the runs on the same graph.