Chem Paper #2 - aka Chemilumenescence

Sadly not all of my pretty pictures copied over - but you'll get the general idea! 

Chemiluminescence

Linda Southard

Nora Mena

Chem 151L-005

Pete Golden

Introduction

           

            The objective of this lab was for our group to identify which chemicals, when mixed together, we could get to glow.  The group additionally was trying to determine in what ratios it would take to make these chemicals glow.   Finally, the group will be attempting to find out which of the chemicals, and in which ratios, will glow for a longer period of time as well as which ones will glow brightest.

            Chemiluminescence is the formation of energy, in the form of a matter we call light.  This is based on a reaction of chemicals mixed together.

            Chemiluminescence is used in a variety of ways.  Some of the ways that Chemiluminescence is used in the scientific world is to analysis an inorganic substance/species in that of a liquid phase.  It can also be used in the detection of biomolecules, which are any molecules produced from any living organism, in some systems like ELISA (Enzyme-lined immunosorbent assy.  ELISA is a popular format when doing “wet-lab" for the detection of the presence of a substance).  Additionally, it is used while working along with DNA. 

            In other capacities, Chemiluminescence is used for the Military while working on Land Navigation training as well as for movements in war times while wanting to maintain “lights out”. Although we like to refer to them as Glow sticks, the U.S. Navy were actually the first to develop the “light stick” method.  The Navy developed them as a subtle and easily concealed form of illumination for those who participated in their special ops, Navy SEALS units when they were dropped behind enemy lines.  It is also used in the Law Enforcement Field while working on murder cases (DNA – Blood) as well as search and rescue divers in muddy waters.  Families use this while they are camping for markers, safety and some people in hurricane or tornado prone areas keep them in their safety and first aid kits.  

            Finally, Chemiluminescence is used in what all children, both young and old, love to play with no matter what time of year it is.  You can find them at fairs, festivals, amusements parks and even in your local Dollar Tree.  These are Glow Sticks. 

            Going back to families and Chemiluminescence, a family can observe it while camping as well as while using it themselves.  While families are out camping, most likely they would see a firefly.  Male fireflies, aka lightening bugs, emit a yellow to green color during their mating process.  Yet another way a family might see Chemiluminescence in nature is by way of taking a hike and coming across a click beetle or a railway worm.  Click Beetles will emit a green to orange glow while the Railway Worm will emit a red light unless they are moving and then they will emit a green light.

If you were to go on a deep sea diving expedition or were one of the persons who were researching the Titanic, then you would have experienced another form of Chemiluminescence.  You would have possibly come across a Jellyfish or other Creatures of the deep.

The fundamentals of this experiment are that the group will take luminol from a powder state, 0.1 g mixed with 1M NaOH [Sodium Hydroxide] until dissolved.  Next, they will pour that in to a Volumetric Flask and add enough distilled water to mix it until it is a full 50 mL mixture.  This will be their stock solution.  The group will then introduce via pipettes, their stock solution to different chemicals and or solutions in a well plate.  The group will then observe how each solution or chemical interacts with the other(s).  They will record the results and determine if their solutions can make a form of chemiluminescence.   The end result and the goal of this experiment is to see which ones they can get to glow the brightest and which will glow the longest.

            Within this experiment the group will be working with different variables.  They will be working with Chemicals, Compounds and solutions.  Some of the products they will use will be:  NaClO (Bleach), H₂O₂ (Hydrogen Peroxide), DMSO (dimethylsulfoxide), 1M HCl (hydrochloric acid) as well as H₂O (water).  (See Fig 1-5.) 

        

Fig. 1               Fig.2                     Fig. 3                      Fig. 4                    Fig. 5

Clorox Bleach Hydrogen            Dimethylsulfoxide  Hydrochloric        Water

                        Peroxide                                              Acid

These are just some of the substances that will be used and worked with in the experiment.  An array of additional chemicals will be available to the group should they decide that they would like to make an attempt to try them.  Within the experiment, these variables will change by way of how much of the stock solution is utilized as well as which chemicals or solutions and how much of each one is used.  The group will control the amounts of each and will report back as to what the results were.

           

RESULTS

Day One Trial

The orders in which the products, chemical and solutions are listed in table 1.1 are the order in which each product, solution, or chemical was placed into the well plate.  Those that show a Zero are ones that were available to the group however none were used in that particular test.  Each test was started with the luminol stock solution being the first to go in to the well plate.  Peroxide was always the second to go in, followed by Bleach each time and then Water.

Table 1.1

Test #	Luminol	H2O2	NaClO	H2O	DMSO	1M HCl	Luminol	NaClO
1	1 drop	1 drop	1 drop	1 drop	Zero	Zero	3 drops	1 drop
2	2 drops	2 drops	1 drop	1 drop	Zero	Zero	3 drops	2 drops
3	3 drops	3 drops	1 drop	1 drop	Zero	Zero	3 drops	3 drops
4	4 drops	4 drops	1 drop	1 drop	Zero	Zero	3 drops	4 drops
5	5 drops	5 drops	1 drop	1 drop	Zero	Zero	3 drops	5 drops
6	6 drops	6 drops	1 drop	1 drop	Zero	Zero	3 drops	6 drops

KEY:

Luminol = the Luminol Stock Solution

H₂O₂ = Hydrogen Peroxide

NaClO = Bleach

H₂O = Water

DMSO = Dimethysulfoxide

1M HCl = Hydrochloric Acid

            You will notice that there is an additional column for Luminol as well as Bleach.  After the initial drops, the group then added additional Luminol and Bleach.  Therefore, they too are included in the order in which they were dropped by pipette into the well plate.

In table 1.2, you will see the results of each test with the brightness, on a scale of 0-5 as well as the length of time for each reaction.

Table 1.2

Test #	Brightness	Length Glow
1		Millisecond
2		Millisecond
3		Millisecond
4		Millisecond
5		Millisecond
6		Millisecond

Brightness Scale Zero to Five, with five being the brightest

                                                                                                                              

         0               1                  2                 3                4                 5

Day Two Trial

The orders in which the products, chemical and solutions are listed in table 2.1 are the order in which each product was placed into the 50 mL beaker.  Our group had opted to utilized information that we had found on line while doing further research.  The group used the remaining portion of the Luminol Stock Solution from the previous week.  Additionally we used some cobalt – to no avail.  The only products that gave our group any semblance of chemiluminescence are the ones listed on table 2.1. 

Day two was started with a 50 mL beaker with measured out 30 mL of H₂O.  Following the water, Bleach was added and finally the Luminol Stock Solution.  The tests that follow are the increments in which the additional products were added and always in the order listed.

Table 2.1

Test #	H2O	NaClO	Luminol	Brightness	Time
1	30 mL	1 drop	20 drops		Flash
2	Zero	1 drop	20 drops		Flash
3	Zero	1 drop	10 drops		2-3 seconds
4	Zero	1 drop	10 drops		5-6 seconds
5	Zero	1 drop	10 drops		7 seconds
6	Zero	1 drop	10 drops		8 seconds
7	Zero	1 drop	10 drops		15-20 seconds

Brightness Scale Zero to Five, with five being the brightest

                                                                                                                              

         0                 1                2                 3                 4                 5

KEY:

Luminol = the Luminol Stock Solution

NaClO = Bleach

H₂O = Water

            When working with chemicals, you have to be more careful than if you are brushing your teeth.  You need to be sure that you aren’t mixing things that shouldn’t be mixed together as well and knowing what you should do if you happen to spill a chemical on your person, your work station or accidently consume the chemical.  One way to ensure that should any hazards happen, i.e. spills etc. is to keep your MSDS on hand.  An MSDS is the Materials Safety Data Sheet.  The MSDS are used whenever you feel you need additional information about any hazardous material or chemical you are working with that is not listed on the products label.  Below are the Chemical Structure of Luminol and the MSDS follows. 

 Material Safety Data Sheet

Luminol

          Luminol is a yellow to green powder, sometimes white.  Luminol causes eye, skin as well as respiratory tract irritations.  The Targeted organs of the human body are the eyes, skin, and mucous membranes.

            Some of the potential Health effects include but are not limited to the following:

            Eyes:   Eye irritation

            Skin:    Skin irritation

            Ingested:  Gastrointestinal irritation with nausea, vomiting and diarrhea

            Inhalation:  Respiratory tract irritation

            In the event of contact, persons should do the following:

            Contact with the eyes:  immediately flush eyes with water for at least 15 minutes contact Poison Control and seek medical aid.

            Contact with the skin:  Flush plenty of water over the skin and remove contaminated clothing/shoes.  Contact Poison Control and seek medical attention if irritation develops and persists.  Wash contaminated clothing prior to wearing again.

            If Luminol is ingested:  Contact Poison Control and seek medical attention.  Do not induce vomiting unless directed to do so by medical personnel.

            If Luminol is inhaled:  Immediately move to cleaner fresher air.  If person who inhaled luminol is not breathing, begin CPR.  If person who inhaled luminol is breathing yet with difficulty, administer oxygen and see medical attention.

            The trial that our group had with the best results was those of day two trials.  We were able to get a 15-20 second “glow” after our seventh step to this trial.  In this trial, we used a total of 30 mL of H₂O, with a total of 7 drops of NaClO and 90 drops of Luminol Stock Solution.  We began with the 30 mL of water then dropped in by drops from a pipette the Bleach and then the Luminol Stock Solution.  This ratio was chosen due to the fact that we were able to get a longer lasting glow which lasted for 15-20 seconds.  Again, we started with the 30 mL of H₂O, 1 drop of NaClO and 20 drops of Luminol Stock Solution (Luminol).  After the initial test, we decided to add one more drop of NaClO followed by another 20 drops of Luminol.  Still not satisfied, we again added one drop of NaClO followed by another ten drops of Luminol.  Seeing more of a result, we decided that we would try to further our results.  We again added one drop NaClO to ten more drops of Luminol.  We noticed more of a glow for a little longer of a time so we thought what the heck, let’s go for more.  We again added only the one drop of NaClO followed by ten more drops of Luminol.  We were satisfied but wanted to go further!  Again we added one drop of NaClO to ten more drops of Luminol.  At this point we had a really nice glow that went for 15-20 seconds and was a nice brightness.  Attempting to see if we could get one to glow for longer, we added additional Bleach and Luminol in the same one and ten drops ratios yet by this time we were unable to get better results due to the solution became a weakened state. 

           

            Oddly, at this point we felt that we were done and decided that we would just amuse ourselves so we began to just mix everything we had, the remainder of our Luminol Stock Solution, Cobalt, Hydrogen Peroxide, Water, Dimethysulfoxide, Hydrochloric Acid and Bleach.  At this point, we actually got our best results.  We sadly did not have any measurements for these.  Every time we added a drop of bleach, we would get a flash of bright green under the meniscus of the fluid while we would get a bright purple flash on the top.  Again we thought we were done so we didn’t take any measurements, just poured and had fun!  Sadly though, it was our best one.

            When we did day one trials, we put all of the luminol in first; this didn’t really generate anything fascinating that was really something to write home about.  We were producing flashes but nothing substantial.  When we researched to see what else we could do, we came to day two trials and began our trial with water and ended it with the Luminol.  By using this sequence of adding the chemicals, we were able to get a brighter and longer lasting color.  We also utilized the same Luminol Stock Solution that we made from day one trials.  Our Luminol stock solution was that of 0.1 g powdered luminol which we added to 1M NaOH until dissolved.  Once dissolved, we poured it in to Volumetric Flask and added enough distilled water to make a 50 mL solution.  This solution was used for BOTH trials.  It held up rather well.

            In day one trials, we made an error in not trying to add the chemicals/solutions in any other order.  We continuously added them in the same order just different amounts.  We should have tried to add them in different orders, not the same over and over again.  By changing the order up some, we would have gotten different results and possibly a better or best result.

            In day two trials, we made the biggest error in thinking that we were done.  We should have still measured our additions even though we were amusing ourselves.  Had we taken measurements on the final additions and in what order we did it, we could have reproduced it for the class on a visual reproduction. 

            If our group were to do this over, we would definitely pay more attention to measurements of chemicals/solutions being added as well as not trying to do this on the smaller scale we did on the first day trials.  Repeating this experiment on a larger scale using more volume of solutions etc. would give us a better and brighter light which would hopefully glow longer.

Conclusion

            In conclusion, day two trial was the better of the two days for trials.  By utilizing fewer chemicals/solutions and making those in the larger volumes made for a better, brighter and longer lasting glow.  By adding the stock solution last, it wasn’t in a weakened state and gave us anything from a bright flash to that of the 15 second glow.