Rates of Reaction - Part 2 | Reactions | Chemistry | FuseSchool
Factors Affecting Reaction Rate
Main Factors Identified
- The main factors affecting reaction rate are concentration, pressure, temperature, and surface area.
Understanding Concentration
- Concentration measures the number of particles in a given volume; it can be increased by adding more particles or reducing the volume.
- In a dilute solution of hydrochloric acid reacting with marble chips, fewer H3O+ ions lead to slower reactions. A concentrated solution increases H3O+ ions, resulting in faster reactions.
Impact of Pressure on Gaseous Reactions
- Pressure affects only gaseous reactions since gases can be compressed while solids and liquids cannot.
- For gas A and gas B to react and form gas C, they must collide with sufficient energy. Increased pressure reduces volume, leading to more fruitful collisions per second and thus a higher reaction rate.
Role of Temperature
- Temperature influences reaction rates by affecting particle kinetic energy; higher temperatures increase average kinetic energy.
- More particles reach activation energy at elevated temperatures, resulting in more fruitful collisions per second and an increased reaction rate.
Surface Area Considerations
- Surface area impacts reaction rates significantly; breaking down solid reactants increases their surface area for interaction.
- The example of hydrochloric acid reacting with marble chips illustrates that smaller pieces allow more H3O+ ions to react simultaneously, enhancing the overall reaction rate.