Rates of Reaction
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. Matches the school marble-chips-and-acid practical, traced against a reference run.
What you can adjust
- Acid concentration
- 0.2 – 2 mol/dm³
- Temperature
- 10 – 60 °C
- Marble form
- 0 – 2
Concentration of the hydrochloric acid, always in excess. The marble (a fixed mass) is the limiting reagent, so every run collects the SAME final volume of gas — doubling the concentration doubles the initial rate and halves the time it takes to finish, but never changes how much gas is produced.
Reaction temperature. Hotter particles move faster and collide more often and more energetically, so the reaction speeds up sharply — roughly doubling every 10 degrees near room temperature.
Breaking the same mass of marble into smaller pieces exposes far more surface area to the acid, so more collisions happen per second and the reaction goes faster — powder reacts fastest, large chips slowest.