In this post, we’ll look at factors that affect the rate of a reaction.
Conditions for reaction to take place
In order for reaction to take place, reacting particles need to collide in the desired orientation, with a certain minimum of energy This energy is known as activation energy.
Activation energy is the minimum energy required for the reaction to take place. If the collision is lesser than activation energy, there is no reaction.
When more particles have energy equal to or greater than activation energy, the more likely the collision will result in a reaction.
Factors affecting the rate of a reaction
Factors Affecting Rate of Reaction 1: Concentration of solution
When the concentration of the solution increases, the amount of particles per unit volume increases. Frequency of collision between reacting particles increases. Rate of reaction increases due to increase in frequency of effective collision.
Factors Affecting Rate of Reaction 2: Pressure of gases
When the pressure of gases increases, the amount of particles per unit volume increases. Frequency collision between reacting particles increases. Rate of reaction increases due to increase in frequency of effective collision.
Factors Affecting Rate of Reaction 3: Particle size of solids
When the size of solids decreases, surface area of the solid particles increases, allowing them to collide with other reacting particles more readily. Rate of reaction increases due to increase in frequency of effective collision.
Factors Affecting Rate of Reaction 4: Temperature
When temperature increases, average kinetic energy of the particles increases. Proportion of particles with energy greater than or equal to activation energy increases. Rate of reaction increases due to increase in frequency of effective collision.
Factors Affecting Rate of Reaction 5: Catalyst
Catalyst increases the rate of reaction by providing an alternative pathway, one with a lower activation energy. More particles will have energy greater than or equal to activation energy. Frequency of effective collision increases, and hence rate of reaction increases.
Note that the catalyst remains chemically unchanged at the end of the reaction.