How to tell something is amphoteric?

Moderators: Chem_Mod, Chem_Admin

Chem_Mod
Posts: 18400
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 435 times

How to tell something is amphoteric?

Postby Chem_Mod » Sun Sep 11, 2011 1:32 am

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?

Chem_Mod
Posts: 18400
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 435 times

Re: How to tell something is amphoteric?

Postby Chem_Mod » Sun Sep 11, 2011 1:33 am

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.

Jacob Loo 1J
Posts: 12
Joined: Fri Sep 26, 2014 2:02 pm

Re: How to tell something is amphoteric?

Postby Jacob Loo 1J » Sat Dec 13, 2014 11:12 pm

What about for other molecules that are not in a similar As2O3 form? How do you tell if they are amphoteric or not?

Juskarun Cheema
Posts: 15
Joined: Fri Sep 25, 2015 3:00 am

Re: How to tell something is amphoteric?

Postby Juskarun Cheema » Sun Nov 29, 2015 11:00 pm

If the compound has both basic and acidic character then it will be amphoteric.

Ann Zhang_1M
Posts: 25
Joined: Wed Sep 21, 2016 2:59 pm

Re: How to tell something is amphoteric?

Postby Ann Zhang_1M » Thu Nov 17, 2016 1:40 pm

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.


Return to “Amphoteric Compounds”

Who is online

Users browsing this forum: No registered users and 1 guest