Amphiprotic substances

[Jennifer_Wong_1G]

Are there any other key amphiprotic substances other than water that we should know? Also, are all amphiprotic substances amphoteric? I'm a bit confused on the relationship between amphoteric and amphiprotic.

[Annie Chang 3G]

I'm not sure about other amphiprotic substances that we should know, but yes, all amphiprotic substances are amphoteric.
Amphiprotic means the substance can both donate and accept a proton, while amphoteric means the substance can act as both an acid and a base.
So, all amphiprotic substances are amphoteric-since when they donate a proton, they are acting as an acid and when they accept a proton, they are acting as a base.

[Vincent Tse 2B]

If you refer to page 148 in the course reader, there is a diagram that highlights all the amphoteric oxides; it's the diagonal band that closely matches the diagonal band of metalloids.

In case it is too hard to see, the following oxides are amphoteric: BeO, Al2O3, Ga2O3, SnO2, PbO2, Sb2O5.