Rate = Change in concentration of reactants or products per unit time.
Factors affecting the rate of reaction.
Temperature
Pressure (only for the reaction of gases)
Concentration
The surface area of reactants
Effect of temperature
The rate of reaction increases with the increase in temperature because
Particles have more Kinetic energy
As a result, they move faster
They collide more frequently
The number of effective collisions increases.
Less time is needed to complete the reaction.
Due to increase in temperature, more particles (reactants) have energy greater
Effect of pressure
The rate of reaction increases with the increase of pressure because
The molecules are closer together.
This results in more gas molecules per unit volume.
Frequency of collision increases
The number of successful collisions increases.
Effect of concentration
The rate of reaction increases with the increase of concentration of reactants as
There are more particles per unit volume
The particles collide more frequently
The number of successful collisions is greater.
Effect of surface area
The rate of reaction increases with the increase of surface area because
More reactants are exposed to react
The reactants collide more frequently
The number of successful collisions increases
Catalyst
A substance that can speed up a chemical reaction by lowering the activation energy by creating an alternative route.
A catalyst remains unchanged after the chemical reaction has been completed.
Catalyst can NOT change the yield of a reaction.
Catalyst cannot change the value of enthalpy change(ΔH).
Catalyst cannot change the position of equilibrium.
Catalyst can be both organic and inorganic substance
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