Chemical Nomenclature Naming and writing Chemical Formulas

Acids If the compound starts with an H it is an acid. (Water doesn’t count) 1. H+element: If the acid has only one element following the H, then use the prefix hydro- followed by the element’s root name and an –ic ending. HCl is hydrochloric acid.

Acids 2. H+ -ate polyatomic ion. If the acid has an “ate” polyatomic ion after the H, then it makes an “ic” acid. H2SO4 is sulfuric acid. 3. H+ -ite polyatomic ion: If the acid has an “ite” polyatomic ion after the H, then it makes an “-ous_ acid. H2SO3 is sulfurous acid.

Ionic Compounds The compound begins with a metal and has a nonmetal bonded to it. Rules 1.Metals commonly form cations simply write their names Transition metals often form more than one positive ion so Roman numerals (in Parentheses) follow the ion’s name NH4+ is ammonium and it is the only positive polyatomic ion you will encounter

Ionic Compounds 2. Nonmetals commonly form anions. Add the suffix “-ide” to the end. 3. So you name the cation then the anion with the “-ide” ending.

PREFIX mono- di- tri- tetra- penta- hexa- hepta- octa- nona- deca- NUMBER Molecular Nomenclature

Naming the Compound The +ion name is given first followed by the name of the negative ion. Use prefixes to indicate the number of atoms of each element. Add “-ide” ending. If the second element’s name begins with a vowel, then the “a” at the end of the prefix is usually dropped.

Formula Writing The prefixes of molecular formulas makes it easy to know how many of each element. Roman Numerals on transition metals tell you the charge of the metal You must REMEMBER the charges on polyatomic ions.