Chemistry 29a M. Walker
NOTES ON EXPERIMENT 9
Chemiluminescence occurs when much of the energy from a chemical reaction is released as light rather than (as is usual) heat. The energy (E) released as light is related to the wavelength (
n) of the light using the equation E = hn, where h is Planck's constant.Experiment 1: Synthesis of Luminol
In this experiment we will begin with the nitrophthalhydrazide already made and dried. You can start the procedure from the second paragraph on p 662. Make sure that you mix well, and do not use the smallest type of tube or it will become over-full. We will not be keeping the filtrate.
Experiment 4: The Light Producing Reaction
Follow the procedure as in the book, but omit the part which says, "Now dilute 5 ml of solution A with 35 ml of water". Make sure you have both solutions A & B, then go into a dark place- there is a closet (which is very dark and therefore more fun), or you may use the instrument room with the lights out. We will not be trying the experiment without hydrogen peroxide, and also I'd rather not have blood spilt in lab!
Lab exam: will be held at 1pm (duration one hour); by 2pm everyone should have completed the exam and we will begin the lab itself at that time. After the experiment (which is short but fun) you will need to write up a brief lab report and hand it in, fill out evaluations and finally check out.
Assigned problems:
Which part of the experiments involves a reduction? What is the reducing agent?
Which part involves an oxidation? What is the oxidizing agent?
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