Factors Affecting Reaction Rates Flashcards
Increasing Temperature
1) the average kinetic energy of the particles is directly proportional to the temperature
2) an increase in temperature increases the average kinetic energy of the reacting particles
3) more particles will have more kinetic energy equal to or greater than the activation energy
4) this will lead to an increase in the chance/frequency of effective collisions
5) hence an increase in temperature increases the reaction rate
Increasing surface area
1) grinding the solid into a powder increases the surface area of contact of the solid
2) There are more particles which are exposed to the chemical reaction
3) there will be more collisions per second between the reacting particles
4) this results in more effective collisions per second
5) this leads to increased reaction rate
Increasing pressure
1) the pressure of a gas is inversely proportional to its volume at a fixed temperature
2) an increase in pressure decreases the volume of a gaseous mixture
3) this will in turn increase the concentration of all reacting gasses
4) the number of gas molecules increases per unit volume
5) this results in more collisions per unit time
6) thus there are more effective collisions per unit time
7) this increases the reaction rate
Adding a Catalyst
1) the addition of a catalyst to a reaction provides an alternative pathway with a lower activation energy
2) this increases the number of particles with sufficient energy to start a reaction than an uncatalysed reaction
3) this increases the chance of effective collisions per unit time
4) this increases the rate of a reaction
Increasing Concentration
1) an increase in concentration means that there are more particles per unit volume
2) this results in more collisions (between reacting particles) per unit time
3) thus, there are more effective collisions per unit time
4) this results in an increased reaction rate
