How do I give a name for the following?

K2CO3
Fe2O3
PbCrO4

Learn the names associated with the negative radical (carbonate, oxide and chromate) and (in the case of iron) the oxidation state of the positive ion. Fe is Fe+3 (ferric) in this case.

The compounds names are potassium carbonate, iron (ferric) carbonate and lead chromate.