The rate of a chemical reaction is influenced by several factors that affect how often and how effectively particles collide.
Key factors:
- Concentration of reactants:
- Higher concentration → more particles → more frequent collisions → faster reaction.
- Temperature:
- Higher temperature → particles move faster → more collisions with enough energy → faster reaction.
- Catalysts:
- Provide an alternate reaction pathway with lower activation energy, increasing the rate without being consumed.
- Surface area:
- For solids, more surface area (e.g., powders vs. chunks) allows more collisions → faster reaction.
- Pressure:
- For reactions involving gases, increasing pressure increases particle density, leading to more collisions → faster reaction.
- Nature of reactants:
- Some substances react faster due to bond strength, molecular complexity, or physical state.
- Inhibitors:
- Substances that slow down or stop reactions by interfering with the reactants or catalysts.
In short: Anything that increases the number or energy of effective collisions speeds up the reaction, while inhibitors slow it down.