How _ affects the rate of reactions:
Sate of matter:It may make a difference whether a medium is aqueous or organic; polar or non-polar; or liquid, solid, or gaseous.
Temperature: an increase in temperature increases in the reaction rate. Temperature is a measure of the kinetic energy, so higher temperature implies higher average kinetic energy of molecules and more collisions per unit time.
Pressure: Increasing the pressure of a reaction improves the chance reactants will interact with each other, thus increasing the rate of the reaction.
Surface area: When you increase the surface area you are increases the chance of collisions between reactant particles. the collisions become more frequent, the rate of reaction increases.
Concentration: A higher concentration of reactants leads to more effective collisions per unit time, which leads to an increased reaction rate except for zero-order reactions. Similarly, a higher concentration of products tends to be associated with a lower reaction rate.
Catalysts: Catalysts lowers the activation energy of a chemical reaction and increase the rate of a chemical reaction without being consumed in the process.