Chemical Nomenclature

What is Chemical Nomenclature?

This is a set of rules to generate systematic names for compounds. The nomenclature used most frequently worldwide is the one created and developed by the International Union of Pure and Applied Chemistry (IUPAC).

The Algorithm

Compound contains Metal

Type I - Non-Transitive Metal

For compounds whose metal is not a transitive metal.

Ionic Binary

These are bonds between a non-transitive metal and a nonmetal.

The name generated for these type of bonds follow this format: $[\text{metal}\text{nonmetal+ide}]$

$CaB{r}_2=\text{Calcium Bromide}$

Ionic Ternary

These are bonds between a non-transitive metal and a polyatomic ion.

Polyatomic ions are ions ( charged substances ) that are composed of two or more elements.

The name generated for these types of bonds follows this format: $[\text{metal}\text{polyatomic ion}]$

$M{g}_3(P{O}_4{)}_2=\text{Magnesium Phosphate}$

For the names of the polyatomic ions, refer to the guide at the end or click here.

Type II - Transitive Metal

For compounds whose metal is a transitive metal. Compounds under this type have a Stock/Systematic name and a Common/Classical name.

Ionic Binary

These are bonds between a transitive metal and a nonmetal.

The name generated for these type of bonds follow the following formats

Stock/Systematic	Common/Classical
$[\text{trans. metal}(\text{OxS})\text{nonmetal+ide}]$	$[\text{latin trans. metal+ous}\text{nonmetal+ide}]$
	$[\text{latin trans. metal+ic}\text{nonmetal+ide}]$

Note: the “-ous” suffix is used to refer to the lesser oxidation state ( $\text{OxS}$ ) of a given element; and the “-ic” suffix is used to refer to the greater oxidation state. For a guide on the oxidation states, click here.

$\text{CuCl}=\text{Copper (I) Chloride}=\text{Cuprous Chloride}$

Ionic Ternary

These are bonds between a transitive metal and a polyatomic ion.

The name generated for these type of bonds follow the following formats:

Stock/Systematic	Common/Classical
$[\text{trans. metal}(\text{OxS})\text{polyatomic-ion}]$	$[\text{latin trans. metal+ous}\text{polyatomic-ion}]$
	$[\text{latin trans. metal+ic}\text{polyatomic-ion}]$

$FeS{O}_4=\text{Iron (II) Sulfate}=\text{Ferrous Sulfate}$

Compounds Not Containing Metals

Type III - No Leading Hydrogen

These are molecules or compounds that do not contain a leading hydrogen in their chemical formulas.

Diatomic Molecules

These are molecules composed of 2 atoms of the same elements.

They are referred to only by their element names.

The diatomic atoms are:

• Flourine ( $F_2$ )
• Chlorine ( $C{l}_2$ )
• Bromine ( $B{r}_2$ )
• Iodine ( $I_2$ )
• Nitrogen ( $N_2$ )
• Hydrogen ( $H_2$ )
• Oxygen ( $O_2$ )

Covalent Binary

These are compounds composed of two nonmetals bonded via a covalent bond.

The names generated for these follow this format: $[\text{prefix+nonmetal prefix+nonmetal+ide}]$ The prefixes to be used are the following:

Subscript	Prefix
1	mono-
2	di-
3	tri-
4	tetra-
5	penta-
6	hexa-
7	hepta-
8	octa-
9	nona-
10	deca-

$S_2{O}_4=\text{Disulfur Tetroxide}$

Note: When the first letter of the element is a vowel, the last letter of the prefix can be omitted (Ex. $\text{Tetraoxide}\to \text{Tetroxide}$).

$C{O}_2=\text{Carbon Dioxide}$

Note: When the first element has a subscript of 1, a prefix of “mono-” is not necessary.

Acid

These are elements that contain a leading hydrogen atom in their chemical formula.

Hydrogen + Element

These are bonds between an hydrogen atom and a nonmetal.

The name generated for these type of bonds follow this format: $[\text{hydro+element+ic acid}]$

$HCl=\text{Hydrochloric Acid}$

Hydrogen + Polyatomic Ion

These are bonds between an hydrogen atom and a polyatomic ion.

The name generated for these type of bonds follow the following formats:

Case	Format
Polyatomic Ion ending in “-ate”	$[\text{polyatomic ion+ic acid}]$
Polyatomic Ion ending in “-ite”	$[\text{polyatomic ion+ous acid}]$

$HN{O}_2=\text{Nitrous acid}$

$HN{O}_3=\text{Nitric acid}$

Polyatomic Ions

• Acetate
  • $C{H}_{2}C{O}_2^{-}$ or $C{H}_{2}CO{O}^{-}$
• Ammonium
  • $N{H}_4^{+}$
• Arsenate
  • $As{O}_4^{3-}$
• Arsenite
  • $As{O}_3^{3-}$
• Azide
  • $N_3^{-}$
• Borate
  • $B{O}_3^{2-}$
• Bromate
  • $Br{O}_3^{-}$
• Bromite
  • $Br{O}_3^{-}$
• Carbonate
  • $C{O}_3^{2-}$
• Chlorate
  • $Cl{O}_3^{-}$
• Chlorite
  • $Cl{O}_2^{-}$
• Chromate
  • $Cr{O}_4^{2-}$
• Chromite
  • $Cr{O}_2^{-}$
• Citrate
  • $C_6{H}_5{O}_7^{3-}$
• Cyanate
  • $OC{N}^{-}$
• Cyanide
  • $C{N}^{-}$
• Dichromate
  • $C{r}_2{O}_7^{2-}$
• Dihydrogen Phosphate
  • $H_{2}P{O}_4^{-}$
• Dihydrogen Phosphite
  • $H_{2}P{O}_4^{-}$
• Dithionate
  • $S_2{O}_6^{2-}$
• Dithionite
  • $S_2{O}_4^{2-}$
• Ferricyanide
  • $Fe(CN{)}_6^{4-}$
• Ferrocyanide
  • $Fe(CN{)}_6^{-4}$
• Fulminate
  • $CN{O}^{-}$
• Hydrazide
  • $N_2{H}_3^{2-}$
• Hydrogen Arsenate
  • $HAs{O}_4^{2-}$
• Hydrogen Carbonate
  • $HC{O}_3^{-}$
• Hydrogen Phosphate
  • $HP{O}_4^{2-}$
• Hydrogen Phospite
  • $HP{O}_3^{2-}$
• Hydrogen Sulfate
  • $HS{O}_4^{-}$
• Hydrogen Sulfite
  • $HS{O}_3^{-}$
• Hydroxide
  • $O{H}^{-}$
• Hypobromite
  • $Br{O}^{-}$
• Hypochlorite
  • $Cl{O}^{-}$
• Hypoiodite
  • $I{O}^{-}$
• Iodate
  • $I{O}_3^{-}$
• Iodite
  • $I{O}_2^{-}$
• Isocyanate
  • $NC{O}^{-}$
• Manganate
  • $Mn{O}_4^{2-}$
• Nitrate
  • $N{O}_3^{-}$
• Nitrite
  • $N{O}_2^{-}$
• Oxalate
  • $C_2{O}_4^{2-}$
• Ozonide
  • $O_3^{-}$
• Perbromate
  • $Br{O}_4^{-}$
• Perchlorate
  • $Cl{O}_4^{-}$
• Periodate
  • $I{O}_4^{-}$
• Permanganate
  • $Mn{O}_4^{-}$
• Peroxide
  • $O_2^{2-}$
• Perrhenate
  • $Re{O}_4^{-}$
• Phosphate
  • $P{O}_4^{3-}$
• Phosphite
  • $P{O}_3^{3-}$
• Plumbate
  • $Pb{O}_3^{2-}$
• Plumbite
  • $Pb{O}_2^2-$
• Rhenate
  • $Re{O}_4^{2-}$
• Selenate
  • $Se{O}_4^{2-}$
• Selenite
  • $Se{O}_3^{2-}$
• Silicate
  • $Si{O}_3^{2-}$
• Stannate
  • $Sn{O}_3^{2-}$
• Sulfate
  • $S{O}_4^{2-}$
• Sulfite
  • $S{O}_3^{2-}$
• Superoxide
  • $O_2^{-}$
• Thiosulfate
  • $S_2{O}_3^{2-}$
• Tungstate
  • $W{O}_4^{2-}$

Oxidation States

Representative Elements

Note: Group 4A or the Crystallogens can either gain 4 electrons ( $-4$ ) or lose 4 electrons ( $+4$ ).

Transition Elements