How To Name Compounds - Chemistry Nomenclature

Chemistry Notes and Review

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How To Name Compounds - Chemistry Nomenclature.

n order for chemists and other scientists to communicate with each other, a system of nomenclature or naming was agreed upon by the International Union of Pure and Applied Chemistry or IUPAC. You'll hear chemicals called their common names (e.g., salt, sugar, and baking soda), but in the lab you would use systematic names (e.g., sodium chloride, sucrose, and sodium bicarbonate). Here's a review of some key points about nomenclature.

Naming Binary Compounds

Compounds may be made up of only two elements (binary compounds) or more than two elements. Certain rules apply when naming binary compounds:

• If one of the elements is a metal, it is named first.
• Some metals can form more than one positive ion. It is common to state the charge on the ion using Roman numerals. For example, FeCl2 is iron(II) chloride.
• If the second element is a nonmetal, the name of the compound is the metal name followed by a stem (abbreviation) of the nonmetal name followed by "ide". For example, NaCl is named sodium chloride.
• For compounds consisting of two nonmetals, the more electropositive element is named first. The stem of the second element is named, followed by "ide". An example is HCl, which is hydrogen chloride.

Naming Ionic Compounds
In addition to the rules for naming binary compounds, there are additional naming conventions for ionic compounds:

• Some polyatomic anions contain oxygen. If an element forms two oxyanions, the one with less oxygen ends in -ite while the one with more oxgyen ends in -ate. For example:
  NO2- is nitrite
  NO3- is nitrate