The -ides,-ites, and -ates of Chemistry

If anyone knows of a good site that CLEARLY explains the usage and difference between these suffixes for naming chemical compounds, please let me know. Thanks in advance.

alice's picture

Hi gkb, I got a little chemistry in university and I'll give a go at answering in the spirit of sharing what I have and hoping that we have an actual chemist around somewhere who will be able to correct me if I'm wrong.

-ide is often used for the ionic form of an element. So Iodine is the element, usually I2, and then when it's dissolved in water, an electron dissociates from each Iodine atom and the iodide ions are formed. Similarly poisonous chlorine gas Cl2 dissolves in water and forms chloride ions.

Same suffix also found in the oxidation state of compound ions -- for example sulphur forms several different ions, sulfide/sulphide is the ion as above, and then it also forms compound ions with oxygen, in which the oxidation state of the sulphur ion differs. So a sulfate/sulphate is SO4(2-), four oxygens to each sulphur, with two negative charges; a sulphite/sulfite is three oxygens to each sulfur/sulphur, SO3(2-) also with two negative charges as it's the sulfur/sulphur ion that is in a difference oxidation state. There are some more explanations of that on quora. I can attempt a bit more explanation if that doesn't make sense -- how are we doing, reader?

The name issue is complicated further because the suffix -ate is used in biological sciences to indicate an acid, so ascorbate for example is the same thing as ascorbic acid aka vitamin C; citrate is the same thing as citric acid. This is possibly related to what I wrote above because sulfuric/sulphuric acid H2SO4 is a handy place to find the SO4(2-) sulfate/sulphate ion.

(edited for increased clarity, I hope)

Very helpful, thanks. While I was trudging through the webnet, stumbling over oxoanions and so forth, it seemed to me that the naming conventions of chemistry were in a right old mess and no mistake. But if the division and confusion came about becasue of of biochem vs.alchymical chem, that sheds some light on the subject.

alice's picture

Ok great. It struck me while I was hunting around to find good sources that the naming conventions from those two different sources must be confusing to the general reader as there is no obvious difference unless you know both how chemists talk about the ions and how biological scientists do.