Naming Compounds Binary Compounds - composed of two elements 1. Contain a metal and a nonmetal 2. Contain two nonmetals
Binary Ionic Compounds - cation (metal ion) - anion (nonmetal ion) Type I - metal forms only one ion (Table 5.1 p. 125) 1. Cation first, anion second 2. Cation - name the element 3. Anion - change end of element name to -ide
Type 2 - metal forms more than one cation (Table 5.2 p. 128) 1. Cation first, anion second 2. Cation charge is specified by a Roman numeral in parentheses Examples - CuClCu? + Cl - copper(I) chloride
Strategy for binary compounds Decide if the cation has only one charge or can have multiple charges a. If cation has one charge, name both ions b. If cation can have multiple charges, use Roman numeral in parentheses to show the charge
Type III - contains only nonmetals 1. First element in formula is named first using full element name. 2. Second element is named as though it were an anion (-ide ending). 3. Prefixes are used to denote the number of atoms present (Table 5.3 p. 132) 4. Never use mono for naming first element.
Examples BF 3 boron trifluoride NOnitrogen monoxide N 2 O 5 dinitrogen pentoxide
Polyatomic ions - ion composed of several atoms, but are bound together so they act as one unit - Table 5.4 p. 137 -oxyanion - series of polyatomic ions that contain an atom of a given element and different numbers of oxygen atoms ClO - hypochlorite ClO 2- chlorite ClO 3- chlorate ClO 4- perchlorate
Examples Na 2 SO 4 sodium sulfate KH 2 PO 4 potassium dihydrogen phosphate Mn(OH) 2 manganese hydroxide NH 4 ClO 3 ammonium chlorate
Naming Acids Compounds that produce H + ions when dissolved in water 1. If anion does NOT contain oxygen *prefix hydro-, suffix -ic acid Examples H 2 S - hydrosulfuric acid HCl - hydrochloric acid
2. If anion contains oxygen root name of central atom *anion ends with ate - suffix -ic acid Example H 2 SO 4 - sulfate ion - sulfuric acid *anion ends with ite - suffix -ous acid Example HNO 2 - nitrite ion - nitrous acid
Writing formulas from names Use names of elements to write the formula. You must check the charges of the ions (including polyatomic ions) to make sure the net charge on the compound is zero.
Examples calcium chloride Ca 2+ Cl - ---> CaCl 2 dinitrogen pentoxide N2O5N2O5 sodium carbonate Na + CO 3 2- ---> Na 2 CO 3 nitric acid nitrate NO 3- ---> HNO 3 lead(IV) oxide Pb 4+ O 2- ---> PbO 2