In
chemistry, an
amphoteric substance is one that can react with either an
acid or
base (more generally, the word describes something made of, or acting like, two components).
Examples include
amino acids and
water. Many metals, such as
zinc,
tin,
aluminium and
beryllium, have amphoteric oxides.
For example, zinc oxide ZnO reacts differently depending on the pH of the solution:
In acids:
:ZnO + 2H
+ → Zn
2+ + H
2O
In bases:
:ZnO + H
2O + 2OH
- → [Zn(OH)
4]
2-
This effect can be used to separate different
cations, such as zinc from
manganese.
See also
Category:Chemical properties
ca:amfòter
pl:Amfoteryczność
sv:Amfoterisk
it:Anfotero