Rates of reaction

The idea

Mean rate = quantity of reactant used or product formed ÷ time taken. Rate increases with higher concentration, higher gas pressure, larger surface area (smaller pieces), higher temperature and a catalyst. Collision theory: particles must collide with at least the activation energy. Higher temperature makes particles move faster, so they collide more often and more collisions have enough energy. Catalysts provide a different pathway with a lower activation energy and are not used up.

1. Name the factor.
2. Explain using collision frequency.
3. For temperature and catalysts, also explain the energy of collisions.

Watch out A catalyst does not give particles more energy: it lowers the activation energy.