The Chemical Kinetics of Chemiluminescence The Chemical Kinetics of Chemiluminescence Mikinze Jones

Aberdeen Central High School

PurposePurpose

ReactionReaction

MethodsMethods

Data AnalysisData Analysis

1) Prepare the stand that will hold the light sensors. a. The pole was taken out of the base on the ring holder, to create a flat

surface.b. Base was set into the Cenco oven on the top shelf.c. The light sensors were then fed through the holes on top of the oven

in order for the cords to stay out of the way.d. The sensors were placed one on each opposite end, both facing to

the left (when looking straight into the oven), and taped down. The third was placed in the middle of the other two and flipped the other direction (facing right) and taped down.

2) Set the glow sticks in a beaker that is put into the oven. This was so the glow sticks are the same temperature.

3) The oven was then set to the desired temperature.a. The dial was turned to the correct temperature.

4) While the oven is heating up, the LabPro device needs to be set up.a. The LabPro requires adaptor cords in order for the light sensors to

plug into the device. b. Then set up the LoggerPro software.

i. Attach all light sensors and set up the sensors with in the program.ii. The duration of the project needs to be changed as well. In the

toolbar, click on the icon that looks like a graph with a little clock. Enter 1200 in the duration box and change the drop box to minutes instead of seconds. Then change the box that says how many samples are taken to 30.

5) Once the oven is at the desired temperature, double check the setup, and then gather 2 assistants.

6) Give the glow sticks a little shake, count to three then break all three glow sticks at once.

7) Carefully place the glow sticks flush with the end of the light sensor. Start with the furthest back sensor to avoid knocking over any other glow sticks.

8) Close the door, click the collect button and wait until the trial is complete.9) The next day the glow sticks can be thrown away in the trash can, and

then repeat steps 2-8 for the next two trials at the different specified temperatures.

10) Once all the trials are complete, clean all materials used and dispose of properly.

The chemiluminescene reaction will follow first order kinetics. The activation energy will be less than one hundred kJ.

This experiment was designed to measure and determine the chemical kinetics of chemiluminescence. In this project, glow

sticks were the chemiluminescence provider.

MaterialsMaterialsThermometer Tape Cenco OvenGlow Sticks Base of a Ring Holder Computer with LoggerProVernier LabPro 3 Light Probe Sensors Adaptors

Raw DataRaw Data

The graphs represent the intensity of the glow sticks’ light as the time passed. With this data

the order of the reaction and the activation energy can be determined.

Conclusion Conclusion

The chemiluminescence reaction does, in fact, follow first order kinetics. When the temperature of the experiment went up, so did the rate of the reaction. Thus, making the results significant with a P value of 0.001, according to the ANOVA test. Since the results are significant, the null

hypothesis is rejected. The calculated activation energy is less than 100 kJ, with a 47.07 kJ activation energy. With the results provided, my

hypothesis is supported to be correct.

Photos taken by Mikinze Jones

All tables, Charts, graphs and images

are created by Mikinze Jones

PHO

TOS

PHO

TOS

Data Table

Temperature 35˚C 42˚C 52˚Ck1 0.01584 0.02719 0.03965k2 0.01995 0.02841 0.05459k3 0.01787 0.02404 0.04703

Average 0.01789 0.02655 0.04709

Statistical AnalysisStatistical Analysis

Rat

e C

onst

ant (

1/m

in)

52°C42°C35°C

0.06

0.05

0.04

0.03

0.02

Boxplot of Rate Constants

One-way ANOVA: 35˚C, 42˚C, 52˚C An ANOVA one-way (unstacked) test was ran on the data from the table containing the k values. The results that were computed show that the rates of reaction were significantly different based on the temperature.

And a greater temperature sped up the rate of reaction. This is true because the P=value is below 0.005.

Source DF SS MS F PFactor 2 0.0013499 0.0006749 31.10 0.001Error 6 0.0001302 0.0000217Total 8 0.0014801S = 0.004659 R-Sq = 91.20% R-Sq(adj) = 88.27% Individual 95% CIs For Mean Based on Pooled StDevLevel N Mean StDev -+---------+---------+---------+--------35˚C 3 0.017887 0.002055 (-----*----)42˚C 3 0.026547 0.002255 (----*-----)52˚C 3 0.047090 0.007470 (----*-----) -+---------+---------+---------+-------- 0.012 0.024 0.036 0.048Pooled StDev = 0.004659 The graph states that the higher the temperature the faster the reaction went with a higher k value.

H2O2 (aq) + C14H10O4 (aq) + dye --> C6H2Cl3OH + 2CO2 + excited dye

The ln of the values from the original data was taken and graphed against time. This allowed for

the rate law to be determined, making the chemical reaction a 1st order reaction. Also the graphs calculated what the k values are, by the

slope of the line.

To the right is a graph of the average k values from each temperature. The ln was

taken of each average and graphed against inverse temperature (1/T), which is in

Kelvins. With the best fit line between the points, the slope could be determined. The is slope 5661. From this the activation energy

can be calculated by the Arrhenius Equation. [5661(8.314)] /1000=47.07 kJ. The activation

energy is 47 kJ.

HypothesisHypothesis