Sciencemadness Discussion Board - Alcohol Burner Experiments

Alcohol Burner Experiments

murf21 - 27-3-2005 at 18:44

My daughter just got a Chemistry set for Easter and we would like to get some experiments that use our alcohol burner. Please post any experiments you know of from basic to complex.
Thanks for your help.
Kevin Murphy

sparkgap - 27-3-2005 at 18:59

Anyone want to suggest distillation with an alcohol burner?

On a serious note, what chemicals were included in the set? I may be able to suggest something after I find out.

BTW, did that alcohol burner come with the chemistry set? Odd... and how old is your dear offspring?

sparky (^_^)

[Edited on 28-3-2005 by sparkgap]

Darkblade48 - 27-3-2005 at 19:20

LOL, distillation with an alcohol burner

It's weird hearing that they still sell chemistry sets with alcohol burners in them, must be a (relatively) old set then?

Chemicals Included

murf21 - 27-3-2005 at 19:25

Sparky-
Thanks for your reply. My daughter is 8 and no, the burner came seperate from the set. The chemicals included are:
C6H12N4
NaHSO4-H2O
Na2CO3
K4(Fe(CN)6)-3H2O
Ca(OH)2
NH4Fe(SO4)2-12H2O
NH4Cl
CuSO4-5H2O
Phenolphthalein solution.
Thanks for your help.
KEvin

Darkblade48 - 27-3-2005 at 19:28

Well, you could just fool around with the CuSO4. 5H2O by making it anhydrous. Heat some up over the flame of the burner. The water will slowly be driven out and the crystals will turn white (anhydrous). If you want, you can drip some water back onto the anhydrous crystals to turn them back to their hydrated form (colour changes from blue --> white --> blue again).

Also, be advised that it's exothermic, so the crystals will get kind of warm when you drip some water onto them (they'll probably hiss at you too)

Edit: You could use the phenolphthalein to test the pH of things around the house, and if you have some common vinegar (weak solution of acetic acid), you can play around with the Na2CO3 to show your daughter neutralization

[Edited on 28-3-2005 by Darkblade48]

sparkgap - 27-3-2005 at 19:43

What, pray tell, would the "C6H12N4" happen to be? Sorry, I'm not good at determining names from empirical formulae.

Anyway, if water glass (sodium silicate) is handy, the classical crystal garden experiment may be appropriate. Google for details.

Not chemistry, but Nitinol (a.k.a. memory metal) is loads of fun with a burner handy.

sparky (^_^)

Darkblade48 - 27-3-2005 at 19:53

Quote:

Originally posted by sparkgap
What, pray tell, would the "C6H12N4" happen to be? Sorry, I'm not good at determining names from empirical formulae.

sparky (^_^)

C6H12N4 is hexamine.

Another idea for crystal growing are to use sugar, salt, alum, which can all be pretty much found in your local grocery store (the latter in a pharmacy, usually)

Dave Angel - 27-3-2005 at 20:01

If you can bubble the gas from the sodium carbonate neutralisation with vinegar through a solution of Ca(OH)2 in water then CaCO3 will precipitate and make the water go cloudy - a test for CO2! You may need to use deionised water (for car battery top up) to make the solution if tap water makes an initially cloudy solution. If any soda glass tubing came with the set then you may be able to heat this with the burner and bend to form the necessary tube to do the bubbling - or just use some aquarium tubing if you have it. You could try blowing through the tubing into the solution to show that you are breathing out CO2.

You may be able to react the hexamine C6H12N4 with the NaHSO4 in some water and heat to give off an awful formaldehyde stench, but the stuff isn't good for you so just a little wafted whiff if you try it! You may well notice it without trying - it's not easy to miss.

You can make some dilute hydrochloric acid by mixing table salt with the NaHSO4 and bubbling the gas through water. Watch for suck back with these things though - if the heated test tube (I am assuming some came with the set!) cools down it will create a partial vacuum that will suck water back and could crack the tube so lift out before it cools!

sparkgap - 27-3-2005 at 20:08

Ah, yes. I did not recognize hexamine/methenamine at once.

Apologies.

I could suggest uses for this, but since the budding chemist in question is an eight-year old, I will refrain from doing so.

Darkblade48, you may want to go easy on quoting whole posts next time.

Dave, yes, the experiments are most appropriate, but they were hoping to involve the alcohol burner in experimentation. Besides, formaldehyde is a nasty irritant and carcinogen; not something you'd want to expose your little tyke to!

On a slightly off-topic note, if the burner can get hot enough, shaping soda glass tubes with fire is a nice skill to learn. Kids, be careful!

sparky (^_^)

[Edited on 28-3-2005 by sparkgap]

Darkblade48 - 27-3-2005 at 20:09

My mistake, I didn't really think about that. I'll try to me more careful in the future.

And when I saw hexamine, I thought of several...."interesting" experiments that could have been done as well, but I had to refrain myself

Dave Angel - 27-3-2005 at 20:12

Quote:

Originally posted by sparkgap
Dave, yes, the experiments are most appropriate but they were hoping to involve the alcohol burner in experimentation.

And does not the production of HCl gas, formaldehyde and shaping of soda glass tubing I suggested involve the burner?

Experiments

murf21 - 27-3-2005 at 20:16

Thanks for the replies guys. We have been kept busy tonite and I am glad you refrained from the more exotic reactions. My daughter may have enjoyed them but ......We will try the soda glass tubes tomorrow.
Thanks again and if you think of any others we will be happy to give them a try

sparkgap - 27-3-2005 at 20:17

My sleep deprivation is showing in my posts.

Can't read between the lines, can I? Sorry about that.

IMHO, bisulfate is acidic enough to decompose hexamine into ammonia and formaldehyde without the need for heating. As I mentioned earlier, it's a bad idea to expose kids to such.

Kevin, the reactions we were speaking of are not actually, uh, exotic, but just the same we think it inappropriate for a young child. Maybe you can tell her to register here when she's about five years older. Then we'll teach her how to put hexamine to more illuminating ends.

sparky (^_^)

[Edited on 28-3-2005 by sparkgap]

Esplosivo - 28-3-2005 at 02:52

Quite a nice chemistry set, I was given one as a birthday present at the age of 7 and it only contained most of common chemicals which one could obtain by visiting a couple of supermarkets. I had some magnesium filings and cobalt (II) nitrate which made me quite happy

(the latter of which I could not at first figure out what to do with, but still fascinated me because of the red colour). My chemistry set had 2 alcohol burners. What is so strange with alcohol burners anyway?

Anyways, since most of the stuff has been already suggested I would simply suggest heating some ammonium chloride in a (heat resistant) test-tube. It gives white fumes which condense at the mouth of the test-tube. This is a thermal dissociation reaction where NH4Cl breaks down into its 'constituents' ammonia and hydrogen chloride gas, which recombine to give the salt when cold.

Some experiments not involving the sacred fire

could be accomplished with K4(Fe(CN)6)-3H2O, potassium hexacyanoferrate (II). It gives brown precipitates with copper (II) salts and with iron (II) salts and white precipitates with calcium salts. You could also oxidise the ammonium iron (II) sulfate (VI) to ammonium iron (III) sulfate (VI) with some acidified (using NaHSO4 could probably do it) potassium permanganate solution (available at the pharmacy). Hope this helps.

Dave Angel - 28-3-2005 at 07:18

Arghh! I keep trying to type up a post relating to a flame test with some of the salts, some nichrome wire from an old toaster and maybe cleaning with hydrochloric acid, but everytime I post it gives me a forbidden error?

Anyway, now that I've put the idea across, someone else with an internet connection that works should be able to elaborate.

mick - 28-3-2005 at 12:48

copper sulphate can be used to grow a large crystal on a piece of string.
mick

neutrino - 28-3-2005 at 12:49

Flame tests are simple to do at home: make a solution of a salt, dip a q-tip in it and hold this in a flame. The solution on the cotton will start to boil quickly and send small droplets of solution into the fire. The droplets dry instantly and any elements in the droplet give off their characteristic flame spectrums. Boron compounds, for example will give you a green color. Sodium is yellow, potassium is pink, etc.

Dave Angel - 28-3-2005 at 13:23

Ah what an ingeniously simple method neutrino, in fact one could probably get away with using a damp cotton bud

to pick up bits of salt and shove it in the flame as a quick and dirty test.

I'd watch out with the K4(Fe(CN)6) though, as there may be cyanide decomposition products (albeit tiny amounts), which we don't want around the kids!

Esplosivo - 28-3-2005 at 23:20

Quote:

Originally posted by Dave Angel
Ah what an ingeniously simple method neutrino, in fact one could probably get away with using a damp cotton bud

Really the potassium hexacyanoferrate(II) is not a problem. It's toxicity may be compared to table salt. The CN- ligands are strognly bound to the central iron atom. Unless mixed with some concentrated acid, such as sulfuric acid, or some strong oxidizing agent I really doubt that even a very small quantity of HCN or (CN)2 will be evolved. I have this stuff in large quantities, never had problems with it, unlike with KCN.

sparkgap - 29-3-2005 at 02:03

neutrino, doesn't potassium impart a pale violet color to the flame, IIRC?

I agree with Esplosivo. Prussian blue is one of the least labile cyanide compounds, and I'd worry only if it was subjected to temperatures way beyond the reach of an alcohol burner.

Here is a link about flame tests. Makes me remember qualitative analysis way back in undergraduate chemistry!

sparky (^_^)

[Edited on 29-3-2005 by sparkgap]

neutrino - 29-3-2005 at 03:16

I was looking at a picture of it and it looked pink. Pink, pale violet, close enough.

sparkgap - 29-3-2005 at 03:21

It looked purple to me, the last time I performed it. Anyway, the purple is intensified if you view the flame through blue cellophane.

The intensity of sodium's yellow still amazes me...

sparky (^_^)

garage chemist - 29-3-2005 at 07:25

You could heat Ca(OH)2 with NH4Cl, ammonia gas will be given off, detectable by the smell.

Dave Angel - 29-3-2005 at 07:33

Quote:

Originally posted by Esplosivo
Really the potassium hexacyanoferrate(II) is not a problem.....

.....I really doubt that even a very small quantity of HCN or (CN)2 will be evolved. I have this stuff in large quantities, never had problems with it, unlike with KCN.

True enough, but there is a world of difference between the risks we are happy to take with our lives and those a father will take with his daughter's.

I feel we are obligated to mention possible risks, however minor, in such a case.

As for flame colour... it's LILAC!

(edit) Ah yes garage chemist, and then maybe combine the ammonia with HCl gas to see NH4Cl form as a cloud of fine solid particles.

There is of course the experiment where one soaks a bit of cotton wool in ammonia solution and some in HCl solution and places the wool at either end of a glass tube. A ring of white ammonium chloride should form closer to the HCl wool as the heavier HCl molecules diffuse more slowly than ammonia.

[Edited on 3/29/2005 by Dave Angel]

sparkgap - 29-3-2005 at 09:52

Well, about flame colors...

TO EACH HIS/HER OWN!!!

Thinking about it now, should we be recommending experiments using strong acids to an eight-year-old?

sparky (^_^)