Reaction Kinetic : 11.3 Factor Affecting Reaction Rate

• There are 4 factors that affect the rate of reaction which are:
  • concentration
  • particle size
  • pressure
  • temperature

• Concentration
  • the relationship between the rate of reaction and the concentration can be show below:

   

• as concentration increase, the number of molecules per unit volume increase. 
• Therefore, the frequency of collision between the reactant molecules increase.
• the frequency of effective collision also increase hence increase the rate of reaction.

• Particle size
  • The relationship between the rate of reaction and the particle size can be show below:

  

• When the size of particles for the same masses of particles decrease, the total surface area of the particles increase
• The total surface area exposes for the collision increase, hence, the frequency of collision increase
• The frequency of effective collision also increase hence it increase the rate of reaction

• Pressure
  • Only applied for gaseous reactants
  • The relationship between the rate of reaction and pressure of the reactant can be show below:

  

• When the pressure increase, the volume of the reactant decrease.
• The reactant molecules become closer from each other, thus easier to collide
• Therefore, the frequency to collision increase and the frequency of effective collision also increase
• Hence, the rate of reaction increase

• Temperature
  • The relationship between the rate of reaction and temperature of the reactant can be show below :

  

• As the temperature increase, the average kinetic energy of the reactant particles increase
• Thus, it move faster and collide more often thus the frequency of collision increase

The frequency of effective collision also increase hence the rate of reaction increase