1. Quiz
What are the four factors that affect the rate of a chemical reaction?
For a reaction to occur particles must collide with each other, what are the requirements for an effective collision to occur?

2. Factors Affecting Rates of Reaction
Concentration
Number of particles in a certain volume
More particles = more collisions per sec (see animation)
More particles means more have sufficient energy to react.
COPY

3. Factors Affecting Rates of Reaction
Temperature
Faster vibration/movement
More collisions per second
More energy in each collision (so more result in a reaction.)
Increase temp increases rate of reaction
COPY

4. Factors Affecting Rates of Reaction
Surface area
More particles exposed
Greater number of collisions per second
The smaller the pieces the larger the surface area.
Larger SA faster rate of reaction

5. Factors Affecting Rates of Reaction
Catalysts
These are things that help put particles in the correct orientation therefore more successful collision hence faster rate of reaction.
Lowers the energy needed to react
More particles have sufficient energy to react

6. How do chemical reactions happen?
In order for a reaction to happen, particles must come in close proximity or ‘collide’ with each other, however not all collisions are successful.
In order for a reaction to occur successfully the particles must collide with the correct orientation and with the correct energy.

7. Testing how surface area affects the rate of reaction
In pairs grab one test tube each.
One of you put 1 marble chip in a test tube while the other put a small amount of powdered marble in a test tube.
Put in hydrochloric acid at the same time (or put in one then quickly the other) and note down the difference, you may try time it or put in one drop of detergent and record the height of the bubbles.

8. Testing how catalyst affects the rate of reaction
Elephant’s tooth paste-demo

9. Scientific investigation
Scientific investigation usually involves 5 things:
Aim (Why are you doing this?)
Hypothesis (What you think is going to happen?)
Method (which includes how you are going to do the experiment and what equipment you need)
Results (recording and processing of observation)
Conclusions

10. The commandments
1. Thou shalt have title. 2. Thou shalt have axis. 3. Thou shalt have units. 4. Thou shalt have appropriate scales. 5. Thou shalt have intervals. 6. Thou shalt have LOBF if drawing line graph.

11. Someone was reacting substance A with substance B, and recorded the height of the foams produced when difference concentration of substance A was used.
Plot a graph using the data and write a sentence about the pattern shown by the graph.
Concentration of substance A (mol/L)
Height of the foam (cm)
0mol/L (control)
1mol/L 5
2mol/L 9
3mol/L 16
4mol/L 20
5mol/L 27
6mol/L 32
7mol/L 37