KonkreteRocketry
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Never knew you can get H2 so easily
This video seems legit
I never knew making H2 could be as simple as this, from hot Sodium carbonate water solution and aluminum foil, the sodium carbonate could be replaced
by ethanol for this reaction, im not sure but i guess sodium bicarbonate could also do this..
I think its cus the solution dissolve Al2O3 away and aluminum react with water.
http://www.youtube.com/watch?v=ggPWdwcsyqM
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Adas
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I use NaOH when I perform this reaction. It should be faster.
Rest In Pieces!
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Morgan
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I bought some sodium carbonate once from the pool supply section of a hardware store. Maybe the fumes wouldn't be as noxious as NaOH or less likely to
eat your hand if you're careless or not wanting to make an "elaborate" hydrogen collection device. This was in the comments.
NurdRage 3 years ago
"Aluminum is "amphoteric", it dissolves in both acids and bases and is a powerful reducing agent, strong enough to generate hydrogen from
water. It is for this reason it is used for for cleaning silver, as it can reduce silver sulfides to silver metal.
You're getting hydrogen and i'm not getting it (in my video) because you're using sodium carbonate while i used sodium bicarbonate."
"Sodium carbonate is more basic than sodium bicarbonate and is strong enough to activate the amphoterism of aluminum."
[Edited on 20-2-2013 by Morgan]
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DraconicAcid
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Quote: Originally posted by KonkreteRocketry  | | I never knew making H2 could be as simple as this, from hot Sodium carbonate water solution and aluminum foil, the sodium carbonate could be replaced
by ethanol for this reaction, im not sure but i guess sodium bicarbonate could also do this.. |
Why do you think ethanol would do this? Ethanol isn't a base (at least, it's not a base in aqueous solution).
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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blogfast25
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DA:
He sees ethanol as a weak acid, which it is (it's also a weak base: like water it can deprotonate but also accept a proton). It forms ethoxides with
strong alkali like NaOH, KOH etc: e.g. KOC2H5 (KOEt). But it's far too weak an acid to attack aluminium in any meaningful sense of the word. But the
alkali metals are readily attacked by most small primary alcohols, with evolution of hydrogen, a laboratory technique to safely get rid of left-over
alkali metals.
[Edited on 20-2-2013 by blogfast25]
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KonkreteRocketry
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| Quote: Originally posted by DraconicAcid | | Quote: Originally posted by KonkreteRocketry | | I never knew making H2 could be as simple as this, from hot Sodium carbonate water solution and aluminum foil, the sodium carbonate could be replaced
by ethanol for this reaction, im not sure but i guess sodium bicarbonate could also do this.. |
Why do you think ethanol would do this? Ethanol isn't a base (at least, it's not a base in aqueous solution). |
Umm seems ethanol probably could not, but it might speed up if added, cus it dissolves the Al2O3 for the aluminum to be exposed.
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DraconicAcid
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| Quote: Originally posted by KonkreteRocketry | | Quote: Originally posted by DraconicAcid | | Quote: Originally posted by KonkreteRocketry | | I never knew making H2 could be as simple as this, from hot Sodium carbonate water solution and aluminum foil, the sodium carbonate could be replaced
by ethanol for this reaction, im not sure but i guess sodium bicarbonate could also do this.. |
Why do you think ethanol would do this? Ethanol isn't a base (at least, it's not a base in aqueous solution). |
Umm seems ethanol probably could not, but it might speed up if added, cus it dissolves the Al2O3 for the aluminum to be exposed.
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And you expect Al2O3 to be more soluble in ethanol than water because...?
Ethanol is an organic solvent- it is much better at water at dissolving organic molecules and nonpolar molecules. But Al2O3 isn't a nonpolar
molecule, it's a network covalent solid ( http://en.wikipedia.org/wiki/Network_solid ), which means that it will basically not dissolve in any solvent that doesn't react with it. It will
dissolve in strongly basic aqueous solutions due to the formation of aluminate ions; it will dissolve in acidic solutions by forming water and
aluminum ions. Ethanol is barely acidic and barely basic (it can react with very strong acids and bases, but not in aqueous solution), so it will do
neither.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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AJKOER
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OK, CH3OH dissolves Al, but only if there is no (or very little) water present (dry CH3OH). Again, to a lesser extent with Ethanol, but a complete
waste of 200 proof alcohol!
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Nicodem
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Thread Moved
21-2-2013 at 08:36 |
vmelkon
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From my chemistry textbook, , CO3(2-) ion acts as a base to a certain extent.
CO3(2-) + H2O <=> HCO3(-) + OH-
so the reaction generates hydroxide ions, therefore, carbonate solutions are expected to be a little basic.
From there, hydroxide reacts with Al2O3 to make aluminate ion and I guess Al reacts with water.
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ScienceSquirrel
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I suspect that the reaction of sodium carbonate in aqueous solution and aluminium metal will produce a mixture of hydrogen and carbon dioxide as gases
and an aqueous solution of sodium aluminate.
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AJKOER
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Performed the reaction of dissoving Al in a dilute solution of NaHCO3. A white flake precipitate form of Al(OH)3 is slowly formed over days. The Al2O3
is permeated by drop in pH permitting the following reaction:
2 Al + 6 H2O --> 2 Al(OH)3 (s) + 3 H2 (g)
Now, Na2CO3 is more basic than NaHCO3, so it is still possible that an aluminate could form, but not apparent by the NaHCO3 reaction.
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AndersHoveland
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I tried to dissolve aluminum with sodium carbonate, the reaction is very slow. I could not make enough hydrogen to collect any of it.
Sodium hydroxide reacts much faster, and the reaction can be very vigorous.
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Morgan
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Out of frustration I just now went out into my shed and got a bottle of sodium carbonate/pH adjuster. I then used a small beaker and filled it with
150 ml of water and heated it in the microwave. Two tablespoons of sodium carbonate was added and stirred. It completely dissolved. Some crumpled up
Al foil was placed inside the beaker and instantly the reaction took off. I then tried to light the bubbles and also collected the gas in an inverted
cup. It was very hard to get any hydrogen to light, much like in the video, but you could tell it was there, an occasional weak pop could be heard or
the flame from the lighter was briefly excited by the gas.
I also noticed a slight noxiousness to the air, not like CO2 however. Perhaps the steamy mist was carrying some of the sodium carbonate into the air,
akin to how NaOH in hot water becomes annoying. I wonder if magnesium would be any better? Powdered Al or Mg might be more dramatic.
Using hot water and a strong solution really eats up the aluminum. Kind of impressive.
So I went back and tried the experiment again this time using a canning jar lid almost occluding the top of the 200 ml beaker except for the lip
whereupon I was able to get a weak woof sound as the gas was lit with a lighter and the flame front traveled inside the jar.
I happened to see a half gallon milk carton of Tri-Sodium Phosphate all purpose cleaner/powder in my laundry room so I tried that too. It seemed to
work just as well as the sodium carbonate in attacking the aluminum. I only immersed the aluminum for a very short time, not knowing what the reaction
might be. I wonder if TSP contains any traces of fluoride?
http://creationwiki.org/Sodium_phosphate
http://www.freepatentsonline.com/2220818.html
[Edited on 24-2-2013 by Morgan]
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vmelkon
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What does fluoride do to aluminum?
If it contains OH-, yes, it will attack the oxide layer on Al.
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SM2
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The most economical way of making H2 is to activate your Al surface with an Hg salt (chloride, sulphate), and place into water. No need for Lye, no
need for washing soda. Aluminum, when properly exposed, will react with water with the vigorous evolution of H2. The white-ish powder which forms as
a scum on the bottom, is mostly Aluminum OXide. Oh with traces of HG, etc.
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Morgan
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What would you get if you mixed sodium carbonate with tri-sodium phosphate?
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vmelkon
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You still get sodium carbonate and trisodium phosphate.
[Edited on 25-2-2013 by vmelkon]
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Morgan
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So since both alkalis vigorously dissolve aluminum in hot water, would you think both alkalis mixed would dissolve aluminum?
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Lambda-Eyde
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| Quote: Originally posted by SM2 | | The most economical way of making H2 is to activate your Al surface with an Hg salt (chloride, sulphate), and place into water. No need for Lye, no
need for washing soda. Aluminum, when properly exposed, will react with water with the vigorous evolution of H2. The white-ish powder which forms as
a scum on the bottom, is mostly Aluminum OXide. Oh with traces of HG, etc. |
Considering how piss cheap lye is, you'd have to be a really cheap bastard to use Hg salts instead. Solutions containing mercury are a nightmare to
have around and dispose of. I would (and you should) much rather use a few bucks on lye instead of having to deal with a solution of one of the most
horrifying heavy metals that you can get your hands on...
[Edited on 25-2-2013 by Lambda-Eyde]
This just in: 95,5 % of the world population lives outside the USA
Please drop by our IRC channel: #sciencemadness @ irc.efnet.org
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Morgan
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I was reading about some TSP products on the market. You can still buy pure TSP of course but it's less common I gather. Ebay has some for cheap. This
first product contains 75-80% TSP and 20-25% Sodium sesquicarbonate according to the msds.
http://www.hardwareandtools.com/Savogran-10621-TSP-Lb-Heavy-...
http://en.wikipedia.org/wiki/Sodium_sesquicarbonate
http://m1.cdn.hardwareandtools.net/04/049542106214.pdf?Expir...
This next product is a mixture of TSP and sodium carbonate of unknown proportion.
http://www.dap.com/product_details.aspx?product_id=320
"Even cleaning products labeled as TSP may contain other ingredients as well, and may, in fact, be less than half trisodium phosphate.[9]"
http://en.wikipedia.org/wiki/Trisodium_phosphate
In conclusion, my box of TSP, although very old, may have contained sodium carbonate as well. I couldn't find it listed. It's a Bondex brand "The
First Choice of Professionals" "all purpose" in a half gallon carton.
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