Slavakion

Sometime before the end of the year, I'll have to do a science fair project. I was wondering if you TFPers had any ideas? Keep the following in mind

• I'm in AP Chem, so something related to chemistry would be better
• This is a "family" fair, so nothing dangerous (no liquid nitrogen, magnesium, explosives...
• I'm hoping for something fairly interesting (but not nigh impossible)

Any ideas?

NeoRete

Oscillating chemical reactions

I don't know if you've reached this point in your class, but I always thought these were interesting. Basically the setup is that one reaction produces another series of reactants which then go on to react as well, ect, until the first set of reactants are produced and the reaction then cycles. When mixed with indicators, you can have a solution that occilates in color on a certain time cycle (good eye candy for the parents, and easy enough to produce).

I found this site that has a some of the reactions as well as an animation of the color changes about 1/4 down the page:
http://www.faidherbe.org/site/cours/dupuis/oscil.htm

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Charlie was a chemist but Charlie is nomore, what Charlie thought was H2O was H2SO4

Slavakion

That's so awesome! I remember my teacher mentioning this, but she didn't get into any specifics. Watch me get ambitious and have a whole row of these...

On another note, anything I can do at my house that's a little less "family" oriented assuming I have only ordinary household chemicals and a heat source? I think you get my drift -- stuff that's possibly dangerous and therefore much more likely to be visually kickass.

BTW, nice sig...

slimsam1

Mix bleach with ammonia, ignite!

Actually, don't. Unless you want to poison yourself.

I'd also be careful about doing anything explosive, especially if you live in the US.

If you're really ambitious, you could try to make a coud chamber to detect and see hints of solar radiation.

slimsam1

Oh - is there anything you could think of to do with dry ice?

Slavakion

Hmm... that would work... if I wanted to make poison gas...

Dry ice? I dunno. There's always

molloby

Thermite is always fun-

Powdered aluminium and Fe203

Putting potassium permanganate on top and pouring on a bit of glycerol is the classic starter, but anything that generates heat'd do it.

Be extremely carefull if you do do it- lots of smoke and a large glob of molten iron is produced- the reaction has an enthalpy of about -800 kJ/mol

The Magic

Find out what happens when you take some liquid oxygen and mix it with fire....

molloby

What, facial scarring?

NeoRete

Dry ice is really run to play with, seal it in a ballon and it will inflate it if you have enough material in it. It will also "skate" across a counter because the cushion of CO2 gas it gives off cushions it.

"Cooking" with liquid nitrogen is much more fun (but dangerous). Bouncy balls lose their bounce, onions shatter into small fragments, and it can make a half-gallon of ice cream in 30 seconds (I've done this one firsthand). Freezing a metal with liquid nitrogen also signifigantly decreases its resistance. I found a good set of demos at: http://webs.wichita.edu/facsme/nitro.htm

Again this can be very dangerous, this is from the safety page on that website, which gives even me a healthy respect for the stuff:

A back of the envelope calculation indicates that the entire contents of a 10 Liter dewar being spilled in a unventilated 274 square foot room with an 8 foot ceiling would reduce oxygen levels below the 19.5% level where Air Products recommends the use of a respirator. Since most classrooms are larger than this, suffocation does not represent a major danger. When transporting the liquid in a car, however, it is probably a good idea to open a window.

The possibility of freeze burns represents a much more serious danger and is therefore our first concern. This does not mean that the demonstration itself is dangerous, but it does mean you must be careful. Dangers include:

* Nitrogen can spatter (possibly in eyes) while being poured.

* Flying chunks of frozen objects could cause eye injury.

* Students (being children) will want to reach out and touch nitrogen or other cold objects. As mentioned above, contact with nitrogen can cause tissue damage, and this must be prevented.

Therefore specific safety precautions should include:

* Teachers must stress to their students the importance of not touching frozen objects or nitrogen.

* Wear goggles whenever pouring or dumping nitrogen. Nitrogen can spatter into the eyes, and potentially blinding pieces of frozen things can fly around when we drop it.

* Use a glove and / or tongs to handle any object going into or out of nitrogen and to carry the nitrogen dewar.

Teachers should familiarize themselves with the following first aid instructions (excerpted from the Air Products Nitrogen Material Safety Data Sheet) for cryogenic freeze burns just in case the worst happens:

If cryogenic liquid or cold boil off contacts a worker's skin or eyes, frozen tissues should be flooded or soaked with tepid water (105-115F, 41-46C). DO NOT USE HOT WATER. Cryogenic burns which result in blistering or deeper tissue freezing should be seen promptly by a physician.

Remember to stress the importance of not touching liquid nitrogen or frozen objects.

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Charlie was a chemist but Charlie is nomore, what Charlie thought was H2O was H2SO4

NeoRete

I just stumbled on a recipie for the occilating reaction at http://chemistry.about.com/cs/demons.../aa050204a.htm
There are many more ideas at the parent of this site (http://chemistry.about.com/od/demons...nsexperiments/)

Oscillating Clock Demonstration
Introduction

The Briggs-Rauscher reaction, also known as 'the oscillating clock', is one of the most common demonstrations of a chemical oscillator reaction. The reaction begins when three colorless solutions are mixed together. The color of the resulting mixture will oscillate between clear, amber, and deep blue for about 3-5 minutes. The solution ends up as a blue-black mixture.

Materials

* Solution A:
Add 43 g potassium iodate (KIO3) to ~800 mL distilled water. Stir in 4.5 mL sulfuric acid (H2SO4). Continue stirring until the potassium iodate is dissolved. Dilute to 1 L.

* Solution B:
Add 15.6 g malonic acid (HOOCCH2COOH) and 3.4 g manganese sulfate monohydrate (MnSO4 . H2O) to ~800 mL distilled water. Add 4 g of vitex starch. Stir until dissolved. Dilute to 1 L.

* Solution C:
Dilute 400 mL of 30% hydrogen peroxide (H2O2) to 1 L.

You will need:

* 300 mL of each solution
* 1 L beaker
* stirring plate
* magnetic stir bar

Procedure

1. Place the stirring bar into the large beaker.
2. Pour 300 mL each of solutions A and B into the beaker.
3. Turn on the stirring plate. Adjust the speed to produce a large vortex.
4. Add 300 mL of solution C into the beaker. Be sure to add solution C after mixing solutions A + B or else the demonstration will not work. Enjoy!

Notes

This demonstration evolves iodine. Wear safety goggles and gloves and perform the demonstration in a well-ventilated room, preferably under a ventilation hood. Use care when preparing the solutions, as the chemicals include strong irritants and oxidizing agents.

Clean Up

Neutralize the iodine by reducing it to iodide. Add ~10 g sodium thiosulfate to the mixture. Stir until the mixture becomes colorless. The reaction between iodine and thiosulfate is exothermic and the mixture may be hot. Once cool, the neutralized mixture may be washed down the drain with water.

The Briggs-Rauscher Reaction

IO3- + 2 H2O2 + CH2(CO2H)2 + H+ --> ICH(CO2H)2 + 2 O2 + 3 H2O

This reaction can be broken into two component reactions:

IO3- + 2 H2O2 + H+ --> HOI + 2 O2 + 2 H2O

This reaction can occur by a radical process which is turned on when I- concentration is low, or by a nonradical process when the I- concentration is high. Both processes reduce iodate to hypoiodous acid. The radical process forms hypoiodous acid at a much faster rate than the nonradical process.

The HOI product of the first component reaction is a reactant in the second component reaction:

HOI + CH2(CO2H)2 --> ICH(CO2H)2 + H2O

This reaction also consists of two component reactions:

I- + HOI + H+ --> I2 + H2O

I2CH2(CO2H)2 --> ICH2(CO2H)2 + H+ + I-

The amber color results from the production of the I2. The I2 forms because of the rapid production of HOI during the radical process. When the radical process is occurring, HOI is created faster than it can be consumed. Some of the HOI is used while excess is reduced by hydrogen peroxide to I-. The increasing I- concentration reaches a point at which the nonradical process takes over. However, the nonradical process does not produce HOI nearly as fast as the radical process, so the amber color begins to clear as I2 is consumed more quickly than it can be created. Eventually the I- concentration drops low enough for the radical process to restart so the cycle can repeat itself.

The deep blue color is the result of the I- and I2 binding to the starch present in the solution.

Source: B. Z. Shakhashiri, 1985, Chemical Demonstrations: A Handbook for Teachers of Chemistry, vol. 2, pp. 248-256.

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Charlie was a chemist but Charlie is nomore, what Charlie thought was H2O was H2SO4

Slavakion

Too bad it evolves iodine gas. I'm assuming that I won't be near a fume hood.

NeoRete

I checked, you might be able to do this without a fume hood. The disposal for this is very easy, just washes down the sink. I found this at http://chemlearn.chem.indiana.edu/demos/TheOsci.htm.

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Charlie was a chemist but Charlie is nomore, what Charlie thought was H2O was H2SO4

MSD

I know you said no liquid nitrogen, but this is a solution that is quite safe, and certain to attract the biggest crowd of any exhibit.

In a large bowl, combine 2/3 gallon heavy cream, 1/3 gallon whole milk, 8 tsp vanilla extract (no imitations!) and 1 cup sugar. Mix until you have a uniform liquid. Fold in 4 cups of liquid nitrogen and stir for five minutes or until solid.

The mixture will harden so quickly and uniformly that no ice crystals can form to roughen the texture. The result will be a gallon of the smoothest ice cream you've ever tasted.

For even better results, have the ice cream mix on ice, have a mix of various things that can be added (cookie dugh chunks, chocolate sprinkles, chocolate chips, etc.) Take orders and mix each person a custom sundae. Make sure your judges get the first few. Make sure the nitrogen has completely evaporated before you hand them over.


If all else fails, you can try cold fusion.

Slavakion

The thing about no liquid nitrogen wasn't me being cautious. It was a faculty decision after some dumbass last year poured some into a bottle and threw it out a window. Too bad, because eating liquid nitrogen would be awesome.

Cold Fusion? Nah... why don't I just mix up a pot of antimatter?

TwoToTango

The coolest (sorry) liquid nitrogen experiment I ever
saw was:

Fill the tray part of a small matchbox with mercury.

Stick an ordinary wooden ruler into the mercury.

Pour the LN over the matchbox.

Pound nail into board with the resulting hammer.

Of course, you probably have to get EPA clearance
for the mercury these days. Bummer.

By the way, liquid nitrogen ice cream has been a staple at
the Minnesota State Fair for the past two years. It's by far
the best ice cream ever.

Slavakion

Now I want to make a whole LN toolset... that's just awesome, even if you couldn't safely handle the tools.

MSD

They would also melt after a very short time.

Some guy built a particle accelerator in his garage a few years back, I'm sure you could do it



So, how about a coil gun? Kind of like a rail gun, but different construction and method of propulsion. Most weapons referred to as rail guns are actually coil guns with several coils that fire in sequence.

http://www.amazing1.com/electric-guns.htm First one on the page, ony 20 bucks for the plans. Scale it down and you can shoot ball bearings across the room.



Another idea: http://www.emanator.demon.co.uk/bigclive/jacobs.htm Jacob's ladder. They didn't say anything about high voltage, did they?

Slavakion

I'm sure the school would just love that. I'm definitely gonna keep that link though. Summer project with friends, anyone?

As for the Jacob's Ladder, I'm sure parents would love having their children just a few feet away from huge electrical arcs. I'm even leery about it.