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How to tell something is amphoteric?

Posted: Sun Sep 11, 2011 1:32 am
by Chem_Mod
How can you tell that As2O3 or Bi2O3 is amphoteric? They are amphoteric because they are metalloids; however, can you figure it out by writing out a chemical equation for a reaction of these oxides with water like you can do for BaO?

Re: How to tell something is amphoteric?

Posted: Sun Sep 11, 2011 1:33 am
by Chem_Mod
To be amphoteric means that the oxide can react either with acid or base. In the case of As2O3 we have: As2O3 + 6HCl --> 2AsCl3 + 3H2O (reaction with acid) NaOH + As2O3 + 3H2O --> 2Na[As(OH)4] (reaction with base) Something similar would apply to Bi2O3.

Re: How to tell something is amphoteric?

Posted: Sat Dec 13, 2014 11:12 pm
by Jacob Loo 1J
What about for other molecules that are not in a similar As2O3 form? How do you tell if they are amphoteric or not?

Re: How to tell something is amphoteric?

Posted: Sun Nov 29, 2015 11:00 pm
by Juskarun Cheema
If the compound has both basic and acidic character then it will be amphoteric.

Re: How to tell something is amphoteric?

Posted: Thu Nov 17, 2016 1:40 pm
by Ann Zhang_1M
you can check if the compound can form H3O+ or OH- when it react with others.
If the compound can produce both when reacting with different reactants, it is amphoteric.