Rates of Reaction

the speed at which the amount of reactants decreases or the amount of products increases.

(change in concentration,volume,mass)/time

it is the mean rate of reaction throughout the full reaction, in reality is starts fast and slows down

for particles to react, they have to collide with each other with sufficient activation energy. if there isn’t enough the reaction cannot occur and the particles just move apart without reacting.

• the amount of energy the particles have the more energy they can transfer during the reaction the more likely they can surpass the minimum activation energy. meaning number of successful collisions increases • frequency of collisions particles gain kinetic energy, move faster and collide more frequently. if the collisions occur more frequently the chances for successful collisions increases

temperature, pressure, concentration, surface area, catalyst

as the temperature incresaes, particles gain kinetic energy and therefore move faster. So the frequency of collisions increases as well with more energy. This means that these particles are more likely to exceed the minimum activation energy and there will be a higher rate of successful collisions, leading to a higher rate of reaction according to collision theory.

increasing the concentration/pressure increases the particles per unit volume, this increases the frequency of collisions therefore increasing the rate of reaction

how many particles there are per unit volume concentration: solutions pressure: gases

higher surface area means more particles are exposed to collide with eachother. eg a powder instead of small chunks. although same volume, powder can have a higher frequency of collisions. increasing the rate of reaction.

catalyst: substances that speed up reactions without being used up and remain chemically unchanged at the end of the reaction they lower the activation energy by providing an alternative reaction pathway. therefore theres a higher frequency of successful collisions and the rate of reaction increases.