Amphoteric Oxide Aluminum Oxide

Alex Nguyen 3I
Posts: 100
Joined: Fri Sep 25, 2015 3:00 am

Amphoteric Oxide Aluminum Oxide

Can someone explain to me how the reaction between sodium hydroxide, sodium hydroxide, and water works?
I know that aluminum oxide is acting as an acidic oxide here. It's reacting with a base, so shouldn't salt and a water form? Does this have anything to do with the water being involved as a reactant? Is the transition metal complex a salt?
$2NaOH(aq)+Al_{2}O_{3}(s)+3H_{2}O(l)\rightarrow 2Na[Al(OH)_{4}](aq)$

Chem_Mod
Posts: 19614
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 889 times

Re: Amphoteric Oxide Aluminum Oxide

The product sodium tetrahydoxoaluminate is certainly a soluble salt and the (aq) designation implies the presence of water as solvent. The amphoteric aluminum oxide is not particularly soluble in water but in the presence of concentrated NaOH it can be made to act as an acid. This neutralization results in the formation of the salt of the coordination complex and some water takes part in the coordination complex chemistry.