Chemical Nomenclature

This problem set was developed by AKYU

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The following outline is to help you decide how to name a chemical compound. Use it as a flow chart to break down the different systems of naming to determine the name of a compound.

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Formulas and Names of Binary Metal-Nonmetal Compounds

1. The name of the metal is first (ie: NaCl, sodium chloride)
2. The name of the nonmetal has -ide added (ie: NaCl sodium chloride)
3. IF the metal has more than one possible charge
   1. With the Stock Method you must indicate which ion using the charge in roman numerals (ie: FeCl₂ Iron (II) chloride).
   2. Alternatively the common name may be used if the metal has more than one possible ion. Here use the Latin root and then add -ous for the lower charge. -ic for the higher charge.
      1. FeCl₂ ferrous chloride
      2. FeCl₃ ferric chloride
   3. More examples showing the two different systems:
      

      Compound	Stock Method	Common Name
      FeF2	iron (II) fluoride	ferrous fluoride
      FeF3	iron (III)fluoride	ferric fluoride
      Hg2Br2	mercury (I) bromide	mercurous bromide
      HgBr2	mercury (II) bromide	mercuric bromide

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Formulas and Names of Binary Nonmetal-Nonmetal Compounds

1. Systematic Nomenclature:
   1. For names start with element to the left side on the periodic table
   2. add -ide to the second element
   3. use Greek prefixes for number of atoms: mono, di, tri, tetra, penta, hexa, hepta, octa, nona, deca
   4. Example:
      1. CO carbon monoxide
      2. CO₂ carbon dioxide
      3. N₂O₅ dinitrogen pentoxide
2. Common names: -ous and -ic (-ic has greater charge, OR has fewer atoms). Examples:
   

   Formula	Systematic Name	Common Name
   NO	nitrogen monoxide	nitric oxide
   N2O	dinitrogen monoxide	nitrous oxide
   NO2	nitrogen dioxide	nitrogen peroxide
   N2O5	dinitrogen pentoxide	nitric anhydride
   N2O3	dinitrogen trioxide	nitrous anhydride

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Polyatomic Compounds.

1. Names of Polyatomic Ions
   1. Anions are negative, Cations are positive
   2. ammonium ion NH₄¹⁺
   3. -ide ions
      1. CN^1- cyanide
      2. OH^1- hydroxide
   4. Oxyanions
      1. -ate ate more oxygen.
         

         Formula	Name
         NO21-	nitrite
         NO31-	nitrate

      2. Sometimes oxyanions have an extra hydrogen
         

         Formula	Name
         SO42-	sulfate
         HSO41-	hydrogen sulfate (or bisulfate)

      3. If more than two possibilities:
         

         Formula	Name
         ClO1-	hypochlorite
         ClO21-	chlorite
         ClO31-	chlorate
         ClO41-	perchlorate

2. Naming compounds with polyatomic ions
   1. Positive charge species on left (using Stock method or common name)
   2. Negative charge species on right (using name of polyatomic ion)
   3. Use parentheses as needed
      

      Formula	Ions	Name
      BaSO4	Ba2+ and SO42-	barium sulfate
      Ca(NO3)2	Ca+2 and NO31-	calcium nitrate
      Ca(NO2)2	Ca+2 and NO21-	calcium nitrite
      Fe(NO3)2	Fe2+ and NO31-	iron (II) nitrate or ferrous nitrate

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Acids

1. Hydro Acids: Hydro + halogen name + ic
   

   Formula	Name
   HCl	hydrochloric acid
   HF	hydrofluoric acid

2. OxoAcids: polyatomic ion + acid.
   1. Recognize as polyatomic ions with a hydrogen at the beginning of the formula.
   2. Name with -ous and -ic suffix. (Works just like -ite and -ate suffix)
   3. -ic suffix is for acid with more oxygen atoms.
   4. Examples
      

      Formula	Name	Source
      HNO3	nitric acid	nitric from nitrate
      HNO2	nitrous acid	nitrous from nitrite