Rates of reaction
Rate = change in concentration divided by time
- The rate is fastest at the start of the reaction since each reactant has its greatest concentration
- Rate slows as the reaction progresses as the concentration of the reactants decreases
- Rate becomes zero when the reaction stops (normally when one of the reactants have been used up)
The rate of reaction can be affected by different factors
- Temperature - increases the amount of kinetic energy which results in more successful collisions. At higher temperatures the peak moves to the right (higher energy) with a lower height.
- Pressure of gases - the particles are closer together so are more likely to react
- Concentration of solutions - there are more particles that are closer together so collide more frequently
- Catalysts - lowers the activation energy needed and so provides an alternative route.
- Surface area - small pieces have many surfaces for reacting particles to collide with
Measuring the rate of reaction
- Change in gas volume - volume of gas can be recorded by using a gas syringe at various times
- Change in gas pressure - change in gas pressure can be measured by using a manometer
- Change in mass - if a…