Question

An -ate or -ite at the end of a compound name usually indicates that the compound contains what?

Answer 1

An old chestnut; the `"ite"` ending usually designates the next LOWER oxidation state. It generally relates to ions that contain more than one oxygen atom.

Explanation:

Sodium sulfate versus sodium sulfite, `Na_2SO_4` versus `Na_2SO_3`. In the sulfate, sulfur expresses its maximum oxidation state, `S(+VI)`; in the sulfite, `Na_2SO_3`, we have `S(+IV)`.

Take perchlorates, and chlorates: `ClO_4^-` versus `ClO_3^-`, i.e. `Cl(+VII)` versus `Cl(+V)`. And then there are chlorites and hypochlorites. This naming system is a bit old-fashioned, and tends not to be used anymore.