1. Adrian, Fraser, Roderick, Emma
Rates of Reaction
Adrian, Fraser, Roderick, Emma

2. Introduction Define 1) Reaction -Indications 2) Rate of Reaction
Influencing factors:
-Concentration
-Temperature
-Catalyst

3. Objective
Determine how concentration, temperature and catalysts affect the rate of reaction

4. Materials Experiments Materials: Chemical Materials: Equipment
Materials: Safety
1 -
Temperature
3 Alka-Seltzer Tablets
Hot, cold and room temperature water
3 beakers
Measuring cup
Thermometer
stopwatch
-Safety goggles
2 -
Concentration
Vinegar
Water
Baking soda
6 beakers
Dropper
measuring cup
Measuring spoons
Stopwatch
stirring rod
3 -
Catalysts
Manganese Dioxide
Hydrogen Peroxide
2 test tubes
2 balloons

5. Safety Precautions Wear safety goggles at all times
Long hair tied back
Wash hands before and after each experiment
Third Experiment: Catalyst
Chemicals used are explosive
No open flames

6. TEMPERATURE

7. Experiment: Temperature
How does Temperature affect the rate of reaction?
Alka-Seltzer tablets in different temperatures of water

8. Temperature: Procedure
Place 250 mL of water into a beaker
Record the temperature
Gently place the tablet into the beaker
Record the time taken to dissolve
Repeat for hot and cold water

9. Temperature: Observations
Water type
(exact temp)
Time to be dissolved
Other Observations
Hot
62 oC
17.34 seconds
-Large bubbles
-Loud fizzing sound
Room Temp
24 oC
52.24 seconds
-Many bubbles
-Softer fizzing sound
Cold
6 oC
seconds
-Small bubbles
-Soft fizzing sound

10. Temperature: Actual Affects
When the temperature of a substance rises, the particles gain energy
With more energy, the particles move faster
They then collide with the other substance at an increased rate
Less time for the reaction to occur

11. Sources of Error Temperature Exact Time Recorded values could be out
Hard to tell the tablet had completely dissolved

12. Modifications for the Future
For more accurate results:
Conduct the 3 trials at once
Add more temperatures to test

13. Temperature: Conclusion
Temperature directly affects the rate of reaction.
 temperature =  particle movement
 particle movement =  collision
 collision =  rate of reaction
Opposite occurs for a decrease in temperature

14. CONCENTRATION

15. Concentration Experiment
Particle Collision theory: explains how reactions occur, and why there are different rates of reactions based on differences of characteristics

16. Concentration Experiment
Concentration: the amount of a given solute in a solution
Concentration = number of moles / Volume of solution (L)
Unit = mol / L or M
Can also be calculated in Volume / Volume percentage. (Volume of solute / Volume of Solution)

17. Procedure Part A: 1) Tablespoon of baking soda in beaker
2) Mix together 10 mL of vinegar with 5 drops of water
3) Pour the vinegar/water mixture into baking soda
4) Observe and record

18. Procedure Part B: Place a tablespoon of baking soda in beaker
2) Mix together 5 mL of water with 5mL of vinegar
3) Pour the vinegar/water mixture into baking soda
4) Observe and record

19. Procedure Part C: 1) Place a tablespoon of baking soda in beaker
2) Mix together 10 mL of water and 5 drops of vinegar
3) Pour the vinegar/water mixture into the baking soda
4) Observe and record

20. Observations
The reaction that took place was seen like the one shown below

21. Qualitative Observations
Vinegar vs Water
Molarity (mol/L)
Time (seconds)
Qualitative Observations
High Concentration
10 mL vinegar
5 drops of water
0.853 M
15.7
Bubbles Formed
Fizzing
No baking soda leftover
Medium Concentration
5 mL vinegar
5 mL water M
20.95
Less bubbles
Less fizzing
Some baking soda leftover
Low Concentration
5 drops of vinegar
10 mL water M
23.66
Even less bubbles
Even less fizzing
More baking soda leftover

22. Sources of error Time recorded not exact
Hard to see whether reaction complete
Impurities could have resulted in differences in reaction

23. How concentration affects rate of reaction
Higher concentration = more particles of reactants available
More particles = higher frequency
Higher frequency = faster rate of reaction
Concentration is in direct relation to Rate of reaction

24. Concentration affecting rate of reaction
Simulation of Concentration affecting the rate of reaction:

25. Modifications to Experiment
Run all three tests at the same time
Allows for better comparison
More trials
If more tests were conducted = accurate trend

26. Conclusion Concentration in direct relation to Rate of reaction
Higher concentration allows more collisions
Lower concentration limits collisions

27. Application of Concentration
Cleaning detergents
Concentrated soluble soaps such as laundry soaps

28. CATALYSTS

29. Experiment: Catalyst Define Catalyst:
changes the minimum energy needed for a reaction to occur
is not consumed by the reaction

30. Catalyst in Our Experiment
Decomposition of Hydrogen Peroxide
2 H2O2 (aq) + MgO2 (s) → O2(g) + 2 H2O(l) + MgO2 (s)
Hydrogen peroxide Manganese dioxide

31. Procedure Part A Part B Hydrogen Peroxide in test tube
Place balloon on top
Part B
Hydrogen Peroxide and Manganese Dioxide in test tube

32. Observations Presence of catalyst Time Inflation of balloon
General observations
No catalyst
(5 ml
Hydrogen
Peroxide)
30 sec
None
Nothing happened
Catalyst
Manganese dioxide with 5 ml hydrogen peroxide
5 sec
10 sec
Slight inflation of balloon
Production of heat
Balloon went upright, inflated slightly
Test tube got hot

33. Error and Modifications
Oxygen gas could have escaped
Contaminants
Measure exact quantities used
Measure size of inflation (diameter)

34. Conclusion
By itself, the decomposition of hydrogen peroxide into water and oxygen is slow
Manganese dioxide allows this decomposition to take place rapidly
The oxygen produced inflated the balloon on the test tube
2 H2O2 (aq) + MgO2 (s) → O2(g) + 2 H2O(l) + MgO2 (s)

35. Applications of Catalysts
Chemical Industry:
-more $$ if they make products faster
Ex.
-Manufacturers of Nitric Acid use catalyst: Platinum
-Very expensive metal, but only need small quantity which can be reused
Estimate:
-90% all commercially produced chemical products involve catalysts at some stage
Other:
-Energy Processing
-Bulk/Fine Chemicals
-Food Processing

36. Rate of Reaction: Overall Conclusion
It was shown form the three experiments that temperature, concentration and the presence of catalysts, affect the rate of reaction
Concentration and Temperature
-the higher the concentration or temperature, the faster the reaction takes place
Catalysts
-the presence of positive catalysts, such as Manganese Dioxide, speeds the rate of reaction

37. Further research -Surface Area Conduct more experiments -Pressure
-Negative catalysts
-other factors

38. Questions?

39. No Questions.
Perfect.
Now we have some questions for you.

40. What is the definition of a reaction?

41. Summarize the temperature experiment.

42. What is the reason behind the rate of reaction changing with Temperature and Concentration?

43. What is a catalyst ?

44. What was the catalyst used in the decomposition of hydrogen peroxide ?

45. Name 3 other factors that affect the rate of reaction.

46. This now concludes our Presentation
By: Adrian, Emma, Fraser and Roderick