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Non Life Sciences => Chemistry => Topic started by: erickejah on 26/01/2009 19:28:57

Title: How is Hydrogen release from Aluminium
Post by: erickejah on 26/01/2009 19:28:57: How is Hydrogen release from Aluminium. [?] [?]
Is it just temperature affecting its composition?
Title: How is Hydrogen release from Aluminium
Post by: Make it Lady on 26/01/2009 20:02:21: I'm not sure what you mean here. Aluminium clusters and Aluminium alloys can release hydrogen from water but I have never heard of pure Aluminium suddenly releasing hydrogen!!!
Can you clarify your question?
Title: How is Hydrogen release from Aluminium
Post by: erickejah on 26/01/2009 20:17:37: yes, it would be aluminium in close contact with water. ie: a steam generator.
Title: How is Hydrogen release from Aluminium
Post by: Chemistry4me on 26/01/2009 21:40:35: You talking about this?

Quote
By using sodium hydroxide as a catalyst, aluminum and its alloys can react with water to generate hydrogen gas.
http://en.wikipedia.org/wiki/Hydrogen_production

Al + 3H₂O → Al(OH)₃ + 1.5 H₂
Title: How is Hydrogen release from Aluminium
Post by: erickejah on 26/01/2009 22:59:22: Tx,, it is HTE(High-temperature electrolysis) http://en.wikipedia.org/wiki/High-temperature_electrolysis (http://en.wikipedia.org/wiki/High-temperature_electrolysis)
Title: How is Hydrogen release from Aluminium
Post by: Chemistry4me on 26/01/2009 23:02:28: So you found it yourself?
Title: How is Hydrogen release from Aluminium
Post by: erickejah on 26/01/2009 23:11:03: nope, it was through out the links that you posted here, [:o].
I do not always trust in sources like Wikipedia, since anybody can edit it. [:P]
Title: How is Hydrogen release from Aluminium
Post by: erickejah on 26/01/2009 23:12:17: That is way I found myself asking subject matter experts like you. [:)] [:D]
Title: How is Hydrogen release from Aluminium
Post by: Chemistry4me on 26/01/2009 23:14:31: Quote from: erickejah on 26/01/2009 23:12:17
That is way I found myself asking subject matter experts like you. [:)] [:D]
I am humbled by your comment [:I][:I][:I]
Title: How is Hydrogen release from Aluminium
Post by: Chemistry4me on 26/01/2009 23:16:34: Aluminium always has a layer of aluminium oxide on the surface, without this coating it would actually be quite reactive.
Title: How is Hydrogen release from Aluminium
Post by: erickejah on 27/01/2009 03:44:53: cool, does the aluminium oxide works like boron?
Title: How is Hydrogen release from Aluminium
Post by: Chemistry4me on 27/01/2009 04:37:10: Don't know what you mean [???][???][???]
Title: How is Hydrogen release from Aluminium
Post by: Chemistry4me on 27/01/2009 04:42:17: Oh, do you mean like: boron does not react with water and is unaffected by air at ordinary temperatures?
Title: How is Hydrogen release from Aluminium
Post by: lightarrow on 27/01/2009 15:36:32: Quote from: erickejah on 26/01/2009 19:28:57
How is Hydrogen release from Aluminium. [?] [?]
Is it just temperature affecting its composition?
You mean that a ship made of aluminum should dissolve in the water releasing hydrogen? Those stupid people who made them... [;D]
Aluminum reacts with water only in particular cases:
1. with the action of a non-oxidant acid (HCl ecc.)
2. with the action of a base (even soda or, heating, even baking soda)
3. with the action of a catalyzer as Hg or Ga or Hg salts
4. at melting point
5. continously removing mechanically the Al₂O₃ layer
... probably other ways I don't know.
Title: How is Hydrogen release from Aluminium
Post by: erickejah on 28/01/2009 01:57:48: [:)]
Title: How is Hydrogen release from Aluminium
Post by: Chemistry4me on 29/01/2009 03:06:02: Do you pronounce Aluminium: A-lum-in-num or Alu-min-i-um?
Title: How is Hydrogen release from Aluminium
Post by: Bored chemist on 29/01/2009 20:47:48: Quote from: Chemistry4me on 29/01/2009 03:06:02
Do you pronounce Aluminium: A-lum-in-num or Alu-min-i-um?
Correctly.
Title: How is Hydrogen release from Aluminium
Post by: Chemistry4me on 29/01/2009 22:12:06: Yeah? And what might that be?
Title: How is Hydrogen release from Aluminium
Post by: Chemistry4me on 30/01/2009 02:21:49: Water spilt with aluminium (http://www.rsc.org/chemistryworld/News/2009/January/28010901.asp)
Title: How is Hydrogen release from Aluminium
Post by: erickejah on 02/02/2009 01:07:49: (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2Fthumb%2F8%2F87%2FHigh-temperature_electrolysis.png%2F350px-High-temperature_electrolysis.png&hash=d3a1d520480fc7b04196919b92b2195f)
Title: How is Hydrogen release from Aluminium
Post by: Chemistry4me on 02/02/2009 01:14:03: What is the diagram for?
Title: How is Hydrogen release from Aluminium
Post by: lancenti on 02/02/2009 06:52:12: It's an Electrolysis Cell, and it's probably there just because it's pretty.

For the purposes of completeness,

Al₂O₃ with Acid:

Al₂O₃ + 6 HCl → 2 Al³⁺ + 6 Cl^- + 3 H₂O

Al₂O₃ with Base:

Al₂O₃ + 2 NaOH → 2 Na₂Al(OH)₄
Title: How is Hydrogen release from Aluminium
Post by: ...lets split up... on 02/02/2009 07:08:41: Quote from: Chemistry4me on 29/01/2009 03:06:02
Do you pronounce Aluminium: A-lum-in-num or Alu-min-i-um?
You pronounce it Alu-min-i-um, pay no attention to the American's when it comes to pronouncing english words. Under no circumstances would a "nium" sound like a "num". Also, they tend to put emphasis on the wrong vowels.
Title: How is Hydrogen release from Aluminium
Post by: Chemistry4me on 02/02/2009 07:20:19: Okay ...lets split up... you said it! Now prepared to be ripped apart!!!!!!! [:D][:D][:D]
Title: How is Hydrogen release from Aluminium
Post by: lightarrow on 02/02/2009 12:13:25: Quote from: lancenti on 02/02/2009 06:52:12
It's an Electrolysis Cell, and it's probably there just because it's pretty.

For the purposes of completeness,

Al₂O₃ with Acid:

Al₂O₃ + 6 HCl → 2 Al³⁺ + 6 Cl^- + 3 H₂O
Are you sure of this? I don't think HCl is able to dissolve Al₂O₃

Quote
Al₂O₃ with Base:

Al₂O₃ + 2 NaOH → 2 Na₂Al(OH)₄
Actually is NaAl(OH)₄
Title: How is Hydrogen release from Aluminium
Post by: erickejah on 03/02/2009 04:22:13: Quote from: Chemistry4me on 02/02/2009 07:20:19
Okay ...lets split up... you said it! Now prepared to be ripped apart!!!!!!! [:D][:D][:D]
that is way i prefer to say it in spanish: "aluminio"
Title: How is Hydrogen release from Aluminium
Post by: lancenti on 03/02/2009 12:36:44: Hot dilute HCl should be enough to react with aluminium oxide.

... and oops, yes it should be only one Na in NaAl(OH)₄
Title: How is Hydrogen release from Aluminium
Post by: lightarrow on 03/02/2009 13:02:22: Quote from: lancenti on 03/02/2009 12:36:44
Hot dilute HCl should be enough to react with aluminium oxide.
Ok, but it depends on the form in which the oxide is present; with corundum crystals you can wait centuries before dissolving it with HCl [:)]
It have to be in a very non-compact form (tiny particles, or oxide-idroxide, ecc.)