V2O4 dissolves in acids
to give VO
2+ salts Similarly, V2O5 reacts with alkalies as well as acids
to give
43
VO   and
4
VO  respectively The well characterised CrO is basic
but Cr2O3 is amphoteric Potassium dichromate K2Cr2O7
Potassium dichromate is a very important chemical used in leather
industry and as an oxidant for preparation of many azo compounds