Experiment 1
Research Question: How does the temperature of the luminol solution affect the
reaction intensity of the oxidation of luminol?
Aim: To find out how the temperature of the luminol solution affects the reaction
intensity of the oxidation of luminol
Hypothesis: The higher the temperature, the greater the light intensity and the
more intense the reaction
Procedure:
1. Follow Setup Table 1.0 and mix the Bleach oxidization solution first only and
luminol solution. Keep them separate.
2. Divide the bleach solution into 5 test tubes [25ml of solution each]
3. Place one test tube in a cold bath, one aside, and three in a warm bath.
4. Measure out 25ml of the luminol solution.
5. Place a flask in a black box
6. Start a stopwatch and pour the luminol solution and bleach solution in the
test tube set aside in step 3 into the flask in the black box through a funnel.
7. Use the colorimeter to measure light intensity over a period of 2 minutes
8. Stop the stopwatch when the light fades completely. Remove the flask.
9. Record results in Result Table 1.0
10. Pull out one flask in the warm bath when it is at 35oC and place it in the black
box.
11. Repeat steps 4-8 with the flask mentioned in step 9.
12. Repeat steps 9-10 with flasks at 15oC, 45oC and 55oC.
13. Repeat steps 1-11 with the other three oxidizing solutions, and without
mixing the luminol solution again. Reuse the remaining solution mixed in the
first step.
Setup Table 1.0
Experiment 1: How temperature affects the intensity of the reaction
Oxidizing Solution [use 25ml each
time]
1) Experiment 1
1) Bleach
7.5ml Bleach in 125ml water
2) Hydrogen Peroxide
7.5ml of hydrogen peroxide in 125ml
water
3) Potassium Periodate
0.1g potassium periodate in 125ml
water
4) Cobalt (II)
Luminol Solution [use 25ml each
time]
 0.4g Luminol
 500ml water
 2g sodium carbonate
 0.25g ammonium carbonate
Divide as per needed
0.1g cobalt (II) nitrate in 125ml water
Experiment 2
Research Question: How does the pH value of the luminol solution affect the
reaction intensity of the oxidation of luminol?
Aim: To find out how the pH value of the luminol solution affect the reaction
intensity of the oxidation of luminol
Hypothesis: The greater the sodium carbonate, the higher the pH value and the
greater the light (and thus reaction) intensity.
Procedure:
1. Follow Setup Table 2.0 and mix the Bleach oxidization solution first only and
luminol solution. Keep them separate.
2. Divide the bleach solution into 5 test tubes [25ml of solution each]
3. Divide the luminol solution into 5 flasks [100ml of solution each]
4. Add 0,1,2,4 or 6g of sodium carbonate to each flask respectively. Set aside.
5. Measure out 25ml of the luminol solution from the flask with no sodium
carbonate in a measuring cyclinder.
6. Place another empty flask in a black box.
7. Start a stopwatch and pour the luminol solution and bleach solution into the
flask in the black box through a funnel.
8. Use the colorimeter to measure light intensity over a period of 2 minutes
9. Stop the stopwatch when the light fades completely. Remove the flask.
10. Record results in Result Table 2.0
11. Repeat steps 4-810 using in turn luminol solution from the flasks with 1,2,4
and 6g of sodium carbonate respectively.
12. Repeat steps 5-11 another three times with the other three oxidizing.
Setup Table 2.0
Experiment 2: How the pH value affects the intensity of the reaction
Oxidizing Solution [use 25ml each
time]
1) Bleach
7.5ml Bleach in 125ml water
2) Hydrogen Peroxide
7.5ml of hydrogen peroxide in 125ml
water
3) Potassium Periodate
Luminol Solution [use 25ml each
time]
1) 500ml water
2) 0.4g luminol
3) 0.25g ammonium carbonate
Divide into 5 flasks and add 0,1,2,4 or 6g
0.1g potassium periodate in 125ml
water
4) Cobalt (II)
0.1g cobalt (II) nitrate in 125ml water
of sodium carbonate respectively. (one at
a time)
Divide further as per needed.
**use sodium hydroxide as a reducing agent if necessary
Result Table 1.0
Temperature Light Intensity
/oC
1) Bleach
2) Hydrogen
Peroxide
Total Reaction Time (seconds)
3)Potassium
Periodate
4)Cobalt (II)
1) Bleach
2)Hydrogen
Peroxide
3)Potassium
Periodate
4)Cobalt (II)
3)Potassium
Periodate
4)Cobalt (II)
15
25
35
45
55
Result Table 2.0
Amount of
Light Intensity
Sodium
Carbonate/g
1) Bleach 2) Hydrogen
Peroxide
6
4
2
0
Total Reaction Time (seconds)
3)Potassium
Periodate
4)
Cobalt (II)
1) Bleach
2) Hydrogen
Peroxide
Sites:
http://www.cmste.uregina.ca/Quickstarts/oxidationofluminol.html
http://www.rsc.org/education/eic/issues/2010Mar/ExhibitionChemistry.asp
http://www.hartnell.edu/faculty/jhughey/Files/Luminol_Inhibition.pdf