1. Factors that Affect Rate of Reaction

2. BIG Idea of Unit Chemicals react together in predictable ways
How to name ionic and covalent compounds
How to balance chemical equations
How to identify the common types of reactions
TODAY.. What factors affect the rate at which these reactions occur?

3. Outline Rate of reaction Collision Model
4 main Factors & Investigation:
Temperature
Concentration
Surface Area
Catalyst

4. Rate of Reaction Rate of reaction = Quantity of product produced
Time Required
Chemical reactions occur at different rates
Today we will consider some of the key factors that influence the rate of reaction

5. Collision Model
The rate of reaction is effected by the number of collisions of reactant molecules
In order for collisions to be effective, the molecules must collide with sufficient energy
Molecules must also collide with proper orientation

6. Collision Model
Factors we will examine that influence the reaction by:
Increasing the number of collisions OR
Increasing the fraction of collisions that will be successful

7. Factors Affecting Rate of Reaction

8. Temperature
Increases energy of particles due to increase of temperature
Increase speed of particles and there are more successful collisions because molecules to contact one another more readily and with harder force
Therefore increased temperature = increased rate of reaction

9. Concentration
Concentration: the amount of a substance (solute) present in a given volume of solution
“Packing” in more molecules increases the number of collisions
Therefore a more concentrated solution = increased rate of reaction

10. Surface Area
If particles are in the same phase (liquid/liquid or gas/gas) then it is easy for them to mix with each other
This gives particles maximum opportunity to collide
But if one of the reactants is a solid, the reaction can only take place on the SURFACE of the solid
The smaller the size of the particles, the greater the surface area that the reaction can take place in
Therefore, smaller surface area = increased rate of reaction

11. Catalyst
Substance that enhances the rate of chemical reaction without being consumed itself
They decrease the amount of collision energy needed to break bonds and form new ones making the fraction of successful collisions more effective
Catalysts provide an easier path for reactions to follow
Note: An enzyme is a protein compound that acts as a biological catalyst
Therefore presence of catalyst = increased rate of reaction