Chem 20 - Naming Compounds

We use the word "acid" to expresses the presence of H in the formula, but only if the compound is actually an acid. The first naming scheme below always works, the second works for oxyacids only.

Naming Inorganic Compounds: Try a new formula

Click here to see the Legend. See also: typical oxidation numbers


			or	an Oxyanion

		Naming Scheme 1: A polyatomic combination (other than oxyanions).	or	Naming Scheme 2: The polyatomic ion is an oxyanion. The resulting formula is an Oxyacid (= Oxoacid), and thus makes no mention of the Hydrogen in the name. This is unlike Binary Acids which do use the word Hydro- to designate the Hydrogen.

				morphed oxyanion name + acid
This naming scheme always works, and can be applied equally to oxyanions.
				compose the morphed oxyanion name:
If there is only one H present, then:		There are n Hydrogen atoms, and n > 1, then:		if the original oxyanion has either suffix:
	or

		Greek Prefix + Hydrogen + Name.		-ATE suffix	-ITE suffix
				remove this suffix	remove this suffix
Hydrogen + Name.
Never prefix the first hydrogen if there is only one such, with mono-.				and replace w/ -IC suffix	and replace w/ -OUS suffix
				next append the word acid.

Examples

	Oxyanion in the formula	Scheme 2 not always applicable.	Scheme 1 can always be applied.
HCO₃^-	CO₃^2- = Carbonate	This is an ion, derived from an acid (deprotonated). It is mildly alkaline (basic) and thus not an acid.	Hydrogen Carbonate

H₂CO₃	CO₃^2- = Carbonate	the acid name = Carbonic acid	Dihydrogen Carbonate

H₂SO₄	SO₄^2- = Sulfate	the acid name = Sulfuric acid	Dihydrogen Sulfate

H₃PO₄	PO₄^3- = Phosphate	the acid name = Phosphoric acid	Trihydrogen Phosphate

HCN		weakly acidic: Hydrocyanic acid	Hydrogen Cyanide

Notes

Use Scheme 1 if you are not sure if the compound is an acid.

See polyatomic examples #1.

See polyatomic examples #2.

see ***polyatomic examples #3 (Table P1.6).

see Oxyanions

Greek Prefix

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