crazyboy
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safe easy experiment
My younger brother is in 5th grade and he is learning about chemistry. He asked if I had any cool experiments which I do but…all of them involve
fire or acids or carcinogenics. So do you know any safe but cool experiments to show some 5th graders? I can’t seem to think of any.
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chemkid
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Whats unsafe about a controlled burn? What makes them cool is that they APPEAR unsafe  Boric acid dissolved in denatured alcohol in a dish makes a great green flame.
chemkid
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chemrox
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I found a book for you. I gave to my assitant for his daughters. It's full of things to do with home chems. I'll get the title for you next week.
Meanwhile, besides the flame thing there's the red cabbage indicator. Boild down red cabbage and demonstrate indicators using vinegar, lemon juice
and bicarb. Electrochem, wire lemons in series and use them to run a small motor or LED. (took one out)
[Edited on 13-3-2008 by chemrox]
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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microcosmicus
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Also, have a look at the Golden Book of chemistry experiments. Leaving aside the ones
involving fire or nasty chemicals (perhaps do those as demos) there should be plenty of
ideas there. Also, what is nice about that book is not just that there are cool experiments
to do, but they also systematically introduce the main ideas of the subject, so are worth
doing in order.
Woelen's homepage contains lots of experiments --- steering away from the "everything
the kewl likes" section, you will find plenty of nice experiments. Color changes in
metal ions looks good as does making singlet oxygen which glows in the dark among
other possibilities.
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YT2095
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2 very simple ones and only need very dilute solns, would be the potassium permanganate soln and an iron sulphate crystal, it goes from purple to
clear.
or dilute ammonia soln added to dilute copper sulphate soln, make the soln of CuSO4 dilute enough so that it looks clear like water, it will go deep
blue when you add the Ammonia soln.
another neat one is a Crystal garden, using a soln of sodium silicate (waterglass) and then add a couple of different colored crystals to the top of
this liquid and let them fall, they will grow little "trees" in all different colors.
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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ScienceGeek
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Color changes are VERY interesting, especially to a fifth grader! What about doing some transition metal oxidation states?
Also, you could demonstrate exo- and endothermic reactions, which is very cool as you can feel it
If you have Methylene Blue, you HAVE to do "the Blue Bottle" experiment! 
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YT2095
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another one (one of my Favorites) is to get some filter paper and soak this in silver nitrate soln, let it dry and then spray it with table salt soln
(NaCl) and let this dry in a dark place.
wrap it up in black paper, and take it out 1`st before your demo, ask for a House key off one of the Audience, place the key on the paper and then put
this on a windowsill where there`s Plenty of light.
now do all your demos.
when you`r finished get the filter paper and it should Now have a near perfect image of the key that was resting on it
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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microcosmicus
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| Quote: |
f you have Methylene Blue, you HAVE to do "the Blue Bottle" experiment!
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If you don't have methylene blue, you can pick some up in a pet shop where it
is sold as a medicine for fish with fungal infections. It apparently also serves
as an antidote to cyanide and carbon monoxide poisoning because of its
action as an oxidizer. For a description of this experiment, look here:
http://www.chem.leeds.ac.uk/delights/texts/expt_1.html
Speaking of colorful organic oxidizations, you could combine this with ScienceGeek's
first suggestion and do Fehling's reaction where oxidize your aldehyde (such as glucose)
using copper.
http://www.chemie.uni-regensburg.de/Organische_Chemie/Didakt...
As for the tartarate, you can use cream of tartar and increase the amount of alkali accordingly.
They're never too young to turn them on to organic chemistry If you get them
early enough,
they might even turn out like the geeks in the "totally synthetic" thread
[Edited on 14-3-2008 by microcosmicus]
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ScienceGeek
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Thank you for elaborating for me, microcosmicus
Also, as you mentioned the Fehling's test for aldehydes (reducing sugars), you could do other "Food Tests" as well.
Examples:
Test for Starch using Iodine
Test for protein using Copper Sulfate in KOH or NaOH
Test for fat by rubbing against filter paper.
This is interesting in many levels: Practical applications for chemistry, building blocks of food, qualitative analysis...
Also, a bit more dangerous, one can add a carbohydrate- containing sweet to molten Potassium Chlorate to show the energy stored in a piece of gum, for
instance
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crazyboy
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Thanks guys! I think I will go with the adding ammonia to copper sulfate just as soon as I synth some up. Also I do have about 20mls of methylene blue
for my microscope but am unfamiliar with "the blue bottle experiment" care to elaborate?
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microcosmicus
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Blue bottle experiment?
Basically, it is another experiment in which sugar gets oxidized.
Because the methylene blue changes color depending on its
oxidization state, a bottle filled with an alkaline solution of methylene
blue and sugar turns blue when one adds gas which oxidizes the
dye and turns clear again as the sugar reduces it.
For further information, UTSE, :
http://www.chem.leeds.ac.uk/delights/texts/expt_1.html
http://www.ubclts.com/node/254
http://faculty.mansfield.edu/bganong/biochemistry/bluebott.h...
http://genchem.chem.wisc.edu/demonstrations/Gen_Chem_Pages/0...
[Edited on 15-3-2008 by microcosmicus]
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Jor
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| Quote: | Originally posted by YT2095
another one (one of my Favorites) is to get some filter paper and soak this in silver nitrate soln, let it dry and then spray it with table salt soln
(NaCl) and let this dry in a dark place.
wrap it up in black paper, and take it out 1`st before your demo, ask for a House key off one of the Audience, place the key on the paper and then put
this on a windowsill where there`s Plenty of light.
now do all your demos.
when you`r finished get the filter paper and it should Now have a near perfect image of the key that was resting on it |
I think bromide does this even more effectively than chloride. Iodide is too sensitive as far as I know.
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YT2095
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yeah, bromide`s good, you just swap the table salt with a Bromide salt, but the Chloride is a little more forgiving if you get light on it.
but sure, if you`r happy handling silver bromide paper and can keep it in pure dark until you need it Great
I would say to Use a potassium salt though (for either) if you intend to keep it for a while though, as the NaNO3 that gets created is Hygroscopic and
you`ll find your papers go soggy over time (it happened to me).
as for Iodide, I have no idea to be honest, I`v never experimented with it, You`v given me an idea now
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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ScienceGeek
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| Quote: | Originally posted by crazyboy
Also I do have about 20mls of methylene blue for my microscope but am unfamiliar with "the blue bottle experiment" care to elaborate?
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Check this out =)
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name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/OeQtQdSFPXU&hl=en" type="application/x-shockwave-flash"
wmode="transparent" width="425" height="355"></embed></object>
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bfesser
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I was thinking a <a href="http://en.wikipedia.org/wiki/Tollens'_reagent">Tollens' reagent</a> demo would be interesting. I've always
wanted to try it myself, but I don't have the reagents. They shouldn't be hard to obtain, though, and the results are absolutely spectacular (if the
glassware is clean enough). I saw this demo in person for the first time a week or two ago, in a large round bottom flask (probably around 20
L)--very very cool.
For a detailed procedure, don't use Wikipedia. Just Google "Tollens demo" and go from there. Just be sure to read and follow the cautions--if there
are none, you're on a bad website.
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ScienceGeek
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It's not that dangerous, especially for one who "knows" chemicals.
Only thing to keep in mind is that you don't want to get Silver Nitrate or Ammonia on you. If you need to make the Silver Nitrate yourself, don't get
Nitric Acid on you, and don't inhale the fumes given off in the reaction.
To sum it up, The Tollens reagent demo is not very dangerous for someone who has a basic chemical understanding.
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crazyboy
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Yeah I know but I need some silver nitrate and I don't even have any pure silver so I can't make it...
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microcosmicus
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| Quote: |
It's not that dangerous, especially for one who "knows" chemicals.
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While we're at it, let's mention the real danger here --- if the
reagent is allowed to sit around, it becomes explosive so should
be freshly prepared before use and unused reagent should
be destroyed after doing the reaction.
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ScienceGeek
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I am so sorry I forgot to mention that, but microcosmicus is absolutely right!!
Crazyboy: Try finding some Silver used in soldering. I think the silver is pure enough to make Silver Nitrate (assuming you have Nitric Acid)
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crazyboy
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Yes I have nitric acid but doesn't the soldering silver have copper in it?
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ScienceGeek
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I think you can buy pure silver solder from a jewellry supplier.
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