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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: Nata on May 04, 2006, 06:26:10 PM

Title: how to make aluminum hydroxide Al(OH)3
Post by: Nata 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
Title: Re: how to make aluminum hydroxide Al(OH)3
Post by: Alberto_Kravina 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
Title: Re: how to make aluminum hydroxide Al(OH)3
Post by: plu on May 08, 2006, 01:19:57 PM
Al2Cl6 and some base will do the trick
Title: Re: how to make aluminum hydroxide Al(OH)3
Post by: Borek on May 09, 2006, 04:50:02 PM
Quote from: bakegaku on May 09, 2006, 04:35:57 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.
Title: Re: how to make aluminum hydroxide Al(OH)3
Post by: rkaminski on August 03, 2007, 09:48:23 PM
Hehe, my favourite method:

Me3Al + 3H2O -> Al(OH)3 + 3CH4
Title: Re: how to make aluminum hydroxide Al(OH)3
Post by: jonnybravo 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!!! :-\
Title: Re: how to make aluminum hydroxide Al(OH)3
Post by: BluRay on December 04, 2010, 04:08:26 PM
Quote from: jonnybravo 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!!! :-\
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.
Title: Re: how to make aluminum hydroxide Al(OH)3
Post by: Hamish 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%
Title: Re: how to make aluminum hydroxide Al(OH)3
Post by: ajkoer 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).