Temperature usually affects reactions - the warmer the temperature, the move Brownian movement so the reaction goes faster. And conversely, the colder the temperature, the slower the reaction.
Particle size - the smaller the particles, the more likely they will cause a reaction with another substance so dissolved substances usually react faster than big chunks. This is why water is so important - it dossolves so many substances that it helps reactions occur faster.
Pressure - the higher the pressure the faster the reaction occurs because the particles are being squished together and are moving faster, so they are more likely to collide and cause a reaction. The lower pressure allows the molecules to move farther apart and there is less of a chance of collision, so the reaction rate is usually slower.
Factors affecting rate of chemical reaction.
- Concentration of the reactants.
- Nature of the reactant.
- Orientatation of reacting species.
- Surface area.
- Intensity of light.
- Nature of solvent.