6.1 reaction rates
TRANSCRIPT
Rate of reaction definition
Rate of reaction is the change in concentration of any one reactant
or product in unit time
Monitoring the rate of production of oxygen from hydrogen peroxide, using
manganese dioxide as catalyst
Monitor the rate by measuring the volume of oxygen evolved over time
H2O2 H2O O2+MnO22 2
Procedure
Record the volume of gas in the syringe every
10 s until there is no increase in the volume of gas
Procedure
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
VOLUME
GAS
cm3
TIME sec
Graph Volume Oxygen v Time
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20
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80
100
120
160
30
140
2010 50 6040 8070 90
VOLUME
GAS
cm3
TIME sec
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20
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80
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302010 50 6040 8070 90
VOLUME
GAS
cm3
TIME sec
What volume of gas was collected
after 30 s ?
120cm3
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80
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140
302010 50 6040 8070 90
VOLUME
GAS
cm3
TIME sec
When maximum
volume of oxygen
obtained
After what time was
the reaction finished ?
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20
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80
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140
302010 50 6040 8070 90
VOLUME
GAS
cm3
TIME sec
When half maximum
volume of oxygen
obtained
When was the reaction half finished
?
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160
140
302010 50 6040 8070 90
VOLUME
GAS
cm3
TIME
What was the instanteous
rate at 30 s ?
Y2=150
Y1=95
X2=50X1=10
Rate= Y2-Y1
X2-X1
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60
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302010 50 6040 8070 90
Rate= 150-95 50-10Rate= 55 40Rate= 1.375 cm3/sec
VOLUME
GAS
cm3
TIME sec
How would the graph change if the solution as
more concentrated ?
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80
100
120
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140
302010 50 6040 8070 90
VOLUME
GAS
cm3
TIME
How would the graph change if the temperature
was higher ?
30
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80
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160
140