2. Background:
Chemical kinetics is the general study of reaction rates. How it is controlled and the mechanism of by which the reaction proceeds from the reactant to the product.
The rate of reaction defined the speed of a reaction from reactant to product. It differs based on the conditions and factors affecting it.
There are five factors affecting reaction rates:
a.Nature of reactants
b.Surface area
c.Concentration
d.Temperature
e.catalyst
3. Objectives
Determine the factors affecting the speed of chemical reactions.
Show/ list how these factors can affect the rate of chemical reaction/
Apply collision theory to explain the rates of reaction.
4. Individual properties of a substance that affects the reaction.
The higher the activity series of the substance (i.e. metals) the higher the reaction rates.
Compounds with high energy bonds or elements with unstable electron configurations are prone to react.
The state of matter also affects reaction rates : gases reacts faster than solid and liquid same with the bonding type, ionic bond type reacts faster than molecular compounds.
Nature of reactants
5. Surface area is the exposed matter of a solid substance.
In a reaction between a solid and an aqueous/liquid/gas substance, increasing the surface area of the solid-phase reactant increases the number of collisions per second and therefore increases the reaction rate.
Surface Area
6. The amount of substance present in a mixture/solution.
The more the substance involved in a solution the faster the reaction rates.
The less the substance involved the slower the reaction rates.
Concentration
7. Reflects the quantity of energy of motion of the component particles.
The higher the temperature in the system of a solution, the higher the reaction rates as the energy increases.
The lower the temperature, the slower the reaction rates as the energy is low.
Temperature
8. •A substance which speeds up a chemical reaction without being chemically changed upon completion of the reaction.
•Catalysts increase the rate by lowering the activation energy (Ea) of a reaction.
•It is not changed by the overall reaction.
Catalyst
9. Collision Theory
The hitting ( colliding ) of molecules which results to reaction ( though there are cases where it doesn’t as the activation energy of a substance is high ).
The reaction of rate in relation with collision theory is low if the activation energy is high.
High concentrations lead to more collisions.
For reactions involving the surface of a solid, the greater the surface area, the more collisions that can occur.
The higher the temperature, the greater the kinetic energy of molecules, leading to more effective collisions.
