1. Rates of Reaction and Particle Size
What affects the rate of a reaction?
Demo?
Starter:
How can I make sugar dissolve faster in water?

2. Success criteria
Must – I can name 5 things that can affect the rate of a reaction.
Should – I can do practical investigations to find out about rates of reaction.
Could – I can write equations to show my reactions

3. Rates of reaction
Chemical reactions occur when particles of reactant collide with enough energy to react.

4. What can affect how quickly collisions happen?

5. Particle Size
Will a sugar lump or a tea spoon of sugar dissolve faster?

6. Demo 1: Burning magnesium
What is the difference between burning powdered magnesium and a piece of magnesium?

7. …jelly chopped into cubes?
2) surface area.
Which will melt faster?
A whole block of jelly.
…jelly chopped into cubes?

8. Why do they dissolve faster?
Because if you compare a the whole jelly with the small pieces, the small pieces have a LARGER SURFACE AREA

9. So what?
The larger the surface area, the more collisions that can happen between the chemicals.

10. Temperature
Will chemicals react faster when it is hot or cold?

11. Results You will ALL do 0, room temperature and 40 degrees.
Each group will use a different method and report back.
WARNING: hot acid is extra dangerous! GOGGLES ON

12. Gas collection method 1

13. Alternative methods
Measure the amount of mass lost in a given time.

14. Gas collection method 2
Apparatus used to investigate the reaction of zinc with dilute sulfuric acid.

15. Results: Temperature / oC Time 1 (sec) 20 40 Conclusion:20 40
Conclusion:
I can see that as the temperature increases the rate of the reaction …………………..
This is because as the temperature increases the ………………………..
Key words: Kinetic energy, particle, collide, react

16. 3) What is a catalyst?
A catalyst is a chemical that speeds up a reaction without being used up.

17. Investigation 1:
Apparatus: Zinc Sulphuric acid Wooden splint Beaker Pipette Copper sulphate solution Test tube
Method Put a piece of zinc into a test tube one third full of sulphuric acid. Test for hydrogen (squeaky pop). Now add a few drops of copper sulphate solution and re-test for hydrogen

18. Investigation 2
Apparatus Hydrogen peroxide Wooden splint Manganese Dioxide Beaker
Method:
Put some hydrogen peroxide into a test tube. Test for oxygen (re-light a glowing splint). Add a small amount of manganese dioxide. Re-test for oxygen.

19. Plenary
Can you think of any other situations at home where surface area has an effect on something.

20. Rate of Reaction and concentration
How does concentration affect the rate of reaction?
Starter:
What can happen when particles collide?

21. Collisions infrequent
Concentration
Reactions in solution involve dissolved paticles that must collide before reaction is possible.
The more crowded (concentrated) the solution, the faster the reaction.
Collisions infrequent
Collisions frequent

22. Lets investigate
AIM: to investigate how concentration affects the rate of a reaction. Follow the instructions on the worksheet to find out how the concentration of sodium thiosulphate affects the rate of a reaction.

23. Results
Complete a line graph of your results

24. Concentration and Rates
The rate of a reaction will increase with an increase in concentration because there are more particles.
The more particles there are, the more reactions will take place

25. Plenary Produce a revision card for each factor. Catalysts
Particle size
Concentration
Temperature
Draw a graph for each.

26. How fast the reactants are used up. How fast the products are made.
3. How can you measure the rate of a chemical reaction?
How fast the reactants are used up.
How fast the products are made.
amount of a reactant used or the amount of product formed
time
Rate of Reaction =
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