The +3 and +5 chlorides of Group 15 react with water with no change in oxidation number usually to give the oxide(hydroxide). The acid-base properties of the oxides-hydroxides depend on the oxidation number and the relative position in the group.
| | nonmetals | semimetals | metal |
| +3 oxides | N2O3 | P4O6 | As2O3 | Sb2O3 | Bi2O3 |
| | acidic
| acidic
| amphoteric
| amphoteric
| basic
|
| +5 oxides | N2O5 | P4O10 | As4O10 | Sb2O5 | Bi2O5 |
| | ––––––––––––––– All acidic ––––––––––––––– |
Note that the trend acidic to basic seen for the +3 Group 13 oxides is seen in this series with the nonmetallic elements having the more acidic oxides. Acidity increases for a given element with oxidation number.
Some important oxides, chlorides, acids and oxyanions are shown on the next page.