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Topic: how to make aluminum hydroxide Al(OH)3  (Read 25022 times)

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Nata

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how to make aluminum hydroxide Al(OH)3
« on: May 04, 2006, 06:26:10 PM »
Could anybody help me with a recipe haw to make aluminum hydroxide Al(OH)3 in the Lab? Or give me a reference material, thanks a lot in advance, Nata

Offline Alberto_Kravina

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Re: how to make aluminum hydroxide Al(OH)3
« Reply #1 on: May 05, 2006, 08:28:10 AM »
Just mix a soluble aluminium salt with ammonia.

Al3+ + 3 NH4OH ?Al(OH)3 + 3 NH4+

If you use NaOH the ppt. dissolves in excess NaOH as a Tetrahydroxoaluminate complex

Offline plu

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Re: how to make aluminum hydroxide Al(OH)3
« Reply #2 on: May 08, 2006, 01:19:57 PM »
Al2Cl6 and some base will do the trick

Offline Borek

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Re: how to make aluminum hydroxide Al(OH)3
« Reply #3 on: May 09, 2006, 04:50:02 PM »
I may be mistaken

You are right. You are mistaken ;)

Al2O3 is very stable in water. It easily dissolves in acidic and basic solutions, but it doesn't react with water as such.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline rkaminski

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Re: how to make aluminum hydroxide Al(OH)3
« Reply #4 on: August 03, 2007, 09:48:23 PM »
Hehe, my favourite method:

Me3Al + 3H2O -> Al(OH)3 + 3CH4

Offline jonnybravo

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Re: how to make aluminum hydroxide Al(OH)3
« Reply #5 on: November 29, 2010, 07:40:38 AM »
Can we use Aluminium Metal + NaOH to make AL(OH)3 or not possible, if so where will Na go!!! :-\

Offline BluRay

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Re: how to make aluminum hydroxide Al(OH)3
« Reply #6 on: December 04, 2010, 04:08:26 PM »
Can we use Aluminium Metal + NaOH to make AL(OH)3 or not possible, if so where will Na go!!! :-\
You can. If the solution is too basic and the oxide is solubilized to form the alluminate, you can dilute the solution with water, and the precipitate will appear.

Offline Hamish

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Re: how to make aluminum hydroxide Al(OH)3
« Reply #7 on: August 02, 2011, 11:58:39 PM »
Hi everyone ,I have Alumium Oxide 95% purity,I wish to make [Al 2O3.3H20] how can I do this and aI require to get this to 64.5%

Offline ajkoer

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Re: how to make aluminum hydroxide Al(OH)3
« Reply #8 on: August 23, 2011, 11:51:56 PM »
Let Al dissolve in a solution of pure aqueous 10% ammonia (give it 12 hours). Higher concentrated ammonia may dissolve other metals impurities.

Al2O3 coating is slowly penetrated producing Al(OH)3 and H2 gas upon the hydrolysis of Al in water.

Separate out (by pouring) obvious impurities (for example, Al foil leaves a black residue of Silicon).

Then, carefully pour out most of the liquid leaving gelatinous Al(OH)3 in a solution of ammonia.

For higher purity, add distilled water, shake and let Al(OH)3 settle out. Repeat. If Iron impurity is suspected, add H2O2 to form insoluble Fe2O3, which can be separated out by careful pouring.

Let evaporate to form pure Al2O3 hydrate (adding ethanol may result in just Al2O3).

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