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Posted: Tue Apr 07, 2009 2:53 pm
by john bunsenburner
and Al2O3 and Na2CO3 makes what?

Posted: Tue Apr 07, 2009 3:01 pm
by CpTn_lAw
Or you could make a light gas gun.
Or you could make a small engine run on 2H.
Or you could try to figure out funny things undiscovered until then.
Or you could try to make a hybrid rocket motor, adding O2.
Or you could try to turn a small portion into a H2 plasma , confiing it with a fast spinning magnétic field directed at the center of the virtual sphere. (Am i getting weirdo and stuff? ... :D )

Or you could try to make a H2 laser. same principle as CO2 ones, but with H2.
Or .....whatever man, have fun and be safe XD

;)

Posted: Wed Apr 08, 2009 1:59 pm
by jimmy101
john bunsenburner wrote:and Al2O3 and Na2CO3 makes what?
Try googling.

Na2CO3 plus water makes hydroxide ions (OH<sup>-1</sup>).

Hydroxide ions dissolve Al2O3, giving Al(OH)3 and Al(OH)4<sup>-1</sup>. Which one you get depends on how much hydroxide there is. Al2O3 and Al(OH)3 are basically insoluble in water. NaAl(OH)4 is much more soluble in water giving Na<sup>+</sup> and Al(OH)4<sup>-1</sup>.

In the reaction of Al metal with hydroxide you must first remove the thin Al2O3 coat to expose the bare metal underneath. So that is the first function of the base, it removes the oxide coat from the aluminum. This takes a while and is why the reaction of hydroxide and aluminum metal takes a while to get started.

The second reaction is that between Al metal and water to produce hydrogen gas;
2 Al + 6 H2O ---> 2 Al(OH)3 + 3 H2
(The aluminum is rusting or burning depending on how you want to look at it.)

Al(OH)3 is a mucky ("geletanous") precipitate and if allowed to form to any great extent it will inhibit the further oxidation of the Al. To prevent this a large excess of hydroxide is used which converts the insoluble Al2(OH)3 to the much more soluble Al(OH)4<sup>-1</sup>. So the hydroxide also helps to prevent precipitation of the Al<sup>+3</sup> salts. Hydroxide is consumed in this process. So, though hydroxide is catalytic in the actual oxidation step it is consumed overall.

Posted: Thu Apr 09, 2009 3:34 am
by john bunsenburner
Ok that is a great post jimmy, really helped me out alot. That means I will have to have a fair amount of aluminium and washing soda(Na2CO3) to make large(r) amounts of H2.
One more question; If I build an oxy-hydrogen torch, I would need a stedy supply of O2. A chlorate candle would fulfill my needs just chlorate, in larger quantities, is hard for me to get. Welding canisters(or other canisters) of O2 would be an alternative just they like getting a bit pricy and would most probably require a welding permit, also the regulaot and othe rparts would make this idea unnatractive for me. Therefore I ask you: How could I get my self a moderately cheep, steady and safe supply of O2?

Posted: Thu Apr 09, 2009 2:19 pm
by jimmy101
Not sure where you are but in the US an oxygen source is easy and fairly cheap. For example, http://www.castlewholesalers.com/BERNZO ... inder.html
Need oxygen specific regulator for it and sutiable hose.

What ever you do be damn careful that you don't get fuel mixing back into the oxygen source (or vice versa).

Posted: Thu Apr 09, 2009 2:28 pm
by john bunsenburner
Well I will see if I can find a bottle of that price at my hardware shop. How about regging; Should I pressurize the H2 with a fridgy and then feed it from a bottle, and just set the flow and pressure twice as hish as with the O2 or is there any easyer, cheeper, way?

Posted: Thu Apr 09, 2009 3:26 pm
by ramses
you could just feed it with air, and you would still get 3700F flames. flow regulators should be used on both hoses, turn on hydrogen, and adjust oxygen or air to get the right mixture and hottest flame. be sure to minimize the enclosed volume containing mixed fuel and air.

if you want chlorate, build a chlorate cell (no link, because that would probably violate the rules.)

Posted: Thu Apr 09, 2009 3:36 pm
by john bunsenburner
Well would it be worth making chlorate for a chlorate candle? Or should I just buy a canister or two? Also do you think it is worth making a whole set up to compress the hydrogen into canisters, or should I attach the barrel inwhich the sodium corbonate and aluminium and water form hydrogen directly to a torch? Really I want to keep the cost of this projectat around 50$. And so I do not want to purchase 200$ regs, tanks and piping.

Maybe it woudl be best if I built a torch head where I can simply adjust the temp by opening and closing the air holes and have a direct feed from the barrel.