The rate of a reaction can be determined by the :
1) rate at which reactants are used up
2) rate at which products are formed
The reaction rate can be expressed in the units : mol.s-1
Five Factors can affect the rate of a reaction between two substances:
1) Concentration (solutions)
2) Pressure (gases)
3) Temperature
4) Catalyst
5) Surface Area – extent of division into smaller pieces (solids)
An increase in concentration, pressure, temperature, or surface area will increase the rate of a reaction.
Increased Concentration
:: more reacting particles are present
> more collisions
> more effective collisions
> higher rate
Increased Pressure
:: the same number of particles are forced closer to each other
> more collisions
> more effective collisions
> higher rate
Increased Temperature
:: the same number of particles are made to move faster; higher kinetic energy
> more collisions
> more effective collisions
> higher rate
Add Catalyst
:: decrease in activation energy
> more collisions
> more effective collisions
> higher rate
Increase Surface Area
:: increase in exposed reacting surface
> higher reaction rate
