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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: eurekah on April 28, 2006, 01:17:01 AM

Title: Need Help with Chem experiment ideas
Post by: eurekah on April 28, 2006, 01:17:01 AM
Alright so I am in a chemistry class at the moment and we are all required to do a science demonstration involving one of the elements.  Now I would like to do something that could in involve explotions, flashes of light, fire, that kinda cool stuff, but nothing to big. 

What i was thinking of is make a colourfull smoke bomb.  I know that saltpeter forms a lto of gas when ignited, so I was thinking  of making one of these but have a mixture of various other materials layered in the saltpeter, so when it burns through each layer a diffrent color is formed....but i would like to try something else.

Anyone got any ideas?? My Chemistry teacher is a fairly interesting person that will pretty much allow anything as long as it doesn't cause too much damage....
thanks
Title: Re: Need Help with Chem experiment ideas
Post by: mike on April 28, 2006, 01:33:05 AM
Does the demonstration have to be with an element?

You could burn magnesium (Mg) ribbons in a bunsen burner flame (safety: goggles, lab coat, lots of heat prodcued, very bright, do not look directly at flame as UV light emitted.)

Sodium (Na) in water (safety: goggles, lab coat, gloves)

Flame tests.
Title: Re: Need Help with Chem experiment ideas
Post by: eurekah on April 28, 2006, 06:02:37 PM
I was talking to him today and he said it doesnt specificaly have to be a single element, so i am open to any experiment pretty much....
Title: Re: Need Help with Chem experiment ideas
Post by: wereworm73 on April 28, 2006, 06:46:33 PM
How about a little ammonium triiodide?  Small amounts of it are sometimes used in school demonstrations, and it doesn't take much to make it explode. You'll have to make it on the spot because it's extremely likely to explode prematurely if you try to store it.
Title: Re: Need Help with Chem experiment ideas
Post by: eurekah on April 29, 2006, 12:16:51 AM
is that the stuff that if you apply pressure to it, it goes off?? i remeber last years sciences class was laying that stuff in the hallway and passer byers would crap their pants when a big bang happens....
Title: Re: Need Help with Chem experiment ideas
Post by: Borek on April 29, 2006, 03:36:17 AM
Don't even try, sounds funny, but it is too easy to loose a finger or two.
Title: Re: Need Help with Chem experiment ideas
Post by: Kenichi on May 02, 2006, 10:12:07 PM
Reactions such as aluminum or sodium with iodine are always fun.  Take iodine crystals and powdered aluminum and then after mixing them together drop some water on it.  Tricycloacetone peroxide is also a fun and easy project. But, not only is it VERY unsafe and almost as sensitive ase the ammonium triodide, your teacher might not want it's synthesis to become common knowledge. As noted before by Mike, flame tests are also pretty. 
  Another idea is to take a couple of pennies and cut them so the zinc inside them is exposed.  Drop them into a test tube with hydrochloric acid (6M is what i used) and then cover the top of the test tube with a balloon.  After collecting the Hydrogen gas which is liberated in the reaction of the zinc and hydrochloric acid you can tie off the end of your balloon and attach it to the end of a stick.  Light a candle on a desk far from any student and then, using the stick, maneuver the balloon over the candle.  boom.
Title: Re: Need Help with Chem experiment ideas
Post by: Kenichi on May 03, 2006, 04:07:19 PM
Aluminum foil can be substituted for the zinc in case there is an issue over the defacing of currency.
Title: Re: Need Help with Chem experiment ideas
Post by: woelen on May 03, 2006, 05:52:41 PM
Spectalular reactions invoving two elements. Not too big, but very nice:

http://woelen.scheikunde.net/science/chem/exps/Al+Br2/index.html
http://woelen.scheikunde.net/science/chem/exps/Cl+I/index.html
http://woelen.scheikunde.net/science/chem/exps/mg+iodine/index.html
http://woelen.scheikunde.net/science/chem/exps/P+Br2+Cl2/index.html
Title: Re: Need Help with Chem experiment ideas
Post by: tennis freak on May 17, 2006, 06:28:54 PM
a couple of demonstrations that my teacher did for our class were:

pouring a little bit of ethanol in one of those giant office water bottle things and then dropping in a match.

The second was filling a balloon with a bit of hydrogen and then putting a candle on a stick near it causing an explosion.

However i do not suggest or promote doing these experiments unless supervised by a professional or if you know what you are doing. A little simpler would be to take mentos and dump them into a 2 liter bottle of coke or something causing a fountain :D
Title: Re: Need Help with Chem experiment ideas
Post by: syko sykes on May 18, 2006, 01:19:38 AM
flame tests are always good, use different elements such as copper, sodium, etc. to get different colors

or get 2 rusty iron balls, wrap one in aluminum foil and bang them together to make a spark

http://www.chemicalforums.com/index.php?PHPSESSID=76730bdb5e1a3b30fbc561ee4bb3ceab&topic=8401.msg39375
that topic should give you some more info on the mentos in coke idea

or put some crystalline KClO4 in a test tube and heat it over a fire until it turns liquid. then drop a gummy bear in and watch the fun. a cheetoh is said to work well too. this should probably be done in a hood though.

[insert disclaimer here]
Title: Re: Need Help with Chem experiment ideas
Post by: mike on May 18, 2006, 01:21:47 AM
Quote
or get 2 rusty iron balls, wrap one in aluminum foil and bang them together to make a spark

Similar to thermite reaction?
Title: Re: Need Help with Chem experiment ideas
Post by: syko sykes on May 21, 2006, 11:20:39 PM
Quote
or get 2 rusty iron balls, wrap one in aluminum foil and bang them together to make a spark

Similar to thermite reaction?
probably similar but on a much smaller scale... i don't think they owuld be too happy with a student doing the thermite reaction in a classroom.
Title: Re: Need Help with Chem experiment ideas
Post by: mrdeadman on May 21, 2006, 11:23:03 PM
Quote
or get 2 rusty iron balls, wrap one in aluminum foil and bang them together to make a spark

Similar to thermite reaction?
it's not that insane like a thermite reaction, all it does is spark.
superoxidizer+gummybears ftw!
Title: Re: Need Help with Chem experiment ideas
Post by: mike on May 21, 2006, 11:25:01 PM
But is it the same reaction as the thermite reaction? I was just wondering what the science behind it was, ie what is the significance of the rust (iron oxide) and aluminum foil? Sounds like the same ingredients for thermite to me.. :)
Title: Re: Need Help with Chem experiment ideas
Post by: mrdeadman on May 21, 2006, 11:28:10 PM
But is it the same reaction as the thermite reaction? I was just wondering what the science behind it was, ie what is the significance of the rust (iron oxide) and aluminum foil? Sounds like the same ingredients for thermite to me.. :)
to make thermite you have to get it really hot right, so just hitting the two isn't going to cause the violence of a true thermite reaction with outrageous amounts of heat and such, ingredients are the same, but the reaction isn't the same, im thinking it has something to do with activation energy. i don't know, what do you think?
Title: Re: Need Help with Chem experiment ideas
Post by: syko sykes on May 21, 2006, 11:33:17 PM
not exactly sure on the reaction and why it causes a spark without being a true thermite reaction as mrdeadman said... i just remember doing the experiment in class and seeing a few people jump when it sparked

if you're looking for visual appeal i wouldn't pick that one out of the one's I (or anyone else) posted. if someone else wanted to offer some insight on the reaction that would be great though ;)
Title: Re: Need Help with Chem experiment ideas
Post by: mrdeadman on May 21, 2006, 11:36:08 PM
here's a good read, peanut butter, haha. http://en.wikipedia.org/wiki/Thermite
Title: Re: Need Help with Chem experiment ideas
Post by: mrdeadman on May 21, 2006, 11:39:54 PM
this is an awesome thermite video: http://video.google.com/videoplay?docid=-7231843493488769585&q=thermite&pl=true
Title: Re: Need Help with Chem experiment ideas
Post by: mike on May 22, 2006, 12:09:36 AM
I have done the thermite reaction loads of times and I light it with permanganate and glycerin and Mg. I think you would find that knocking the two spheres together would provide more than enough energy for the reaction. I reckon it is the thermite reaction on a small and quick scale.
Title: Re: Need Help with Chem experiment ideas
Post by: Organishe on May 22, 2006, 01:44:43 AM
The KClO4 and gummy bear reaction is awesome.  I think the largest safety concern is the bunsen burner, so long as you only have small amounts of the perchlorate around. (you can do it with perhaps a gram, maybe less.  Plus, when you get the gummy bear to shoot across the room, jaws will drop  ;D
Title: Re: Need Help with Chem experiment ideas
Post by: jdurg on May 22, 2006, 10:10:27 AM
The KClO4 and gummy bear reaction is awesome.  I think the largest safety concern is the bunsen burner, so long as you only have small amounts of the perchlorate around. (you can do it with perhaps a gram, maybe less.  Plus, when you get the gummy bear to shoot across the room, jaws will drop  ;D
I agree.  It's an INCREDIBLY impressive reaction that you can do on a VERY small scale and still get very large results.  It sounds like a jet-engine/blow-torch combination when you drop the gummy bear into the molten KClO3.  (BTW, it's KClO3 that is used and not KClO4.  Remember, it's potassium chlorate and not perchlorate).
Title: Re: Need Help with Chem experiment ideas
Post by: billnotgatez on May 24, 2006, 04:05:08 AM
Quote
I have done the thermite reaction loads of times and I light it with permanganate and glycerin and Mg. I think you would find that knocking the two spheres together would provide more than enough energy for the reaction. I reckon it is the thermite reaction on a small and quick scale.

One wonders if this is more like flint striking steel to get a spark.
My understanding is that Thermit reactions are very dependent on concentration of each of the constituents.

I would hope you practice any classroom demonstration before hand with someone watching at a distance in case of problems.