1. Rate of reaction definition
Rate of reaction is the change in concentration of any one reactant or product in unit time

2. Monitor the rate by measuring the volume of oxygen evolved over time
Monitoring the rate of production of oxygen from hydrogen peroxide, using manganese dioxide as catalyst 2
MnO2 O2
H2O2
H2O +
Monitor the rate by measuring the volume of oxygen evolved over time

3. Procedure Record the volume of gas in the syringe every
10 s until there is no increase in the volume of gas

4. Procedure

5. How to start the Reaction and stopwatch at the same time
Pull the thread to tilt test tube, and spill its contents.
At the same time start the stopwatch

6. Graph Volume Oxygen v Time
160
V O L U M E G A S
cm3
140
120
100 80 60 40 20 10 20 30 40 50 60 70 80 90
TIME sec

7. 160
V O L U M E G A S
cm3
140
120
100 80 60 40 20 10 20 30 40 50 60 70 80 90
TIME sec

8. What volume of gas was collected after 30 s ?
120cm3
160
V O L U M E G A S
cm3
140
120
100
What volume of gas was collected after 30 s ? 80 60 40 20 10 20 30 40 50 60 70 80 90
TIME sec

9. When maximum volume of oxygen obtained
160
V O L U M E G A S
cm3
140
120
After what time was the reaction finished ?
100 80 60 40 20 10 20 30 40 50 60 70 80 90
TIME sec

10. When half maximum volume of oxygen obtained
160
V O L U M E G A S
cm3
140
120
When was the reaction half finished ?
100 80 60 40 20 10 20 30 40 50 60 70 80 90
TIME sec

11. What was the instanteous rate at 30 s ?
160
V O L U M E G A S
cm3
Y2=150
140
120
Rate= Y2-Y X2-X1
What was the instanteous rate at 30 s ?
100
Y1=95 80
Rate=
Rate=
Rate= cm3/sec 60 40 20 10 20 30 40 50 60 70 80 90
X1=10
X2=50
TIME

12. How would the graph change if the solution as more concentrated ?
160
V O L U M E G A S
cm3
140
120
How would the graph change if the solution as more concentrated ?
100 80 60 40 20 10 20 30 40 50 60 70 80 90
TIME sec

13. How would the graph change if the temperature was higher ?
160
V O L U M E G A S
cm3
140
120
How would the graph change if the temperature was higher ?
100 80 60 40 20 30
TIME