Ionic Nomenclature Lesson 7 Nomenclature • a branch of taxonomy concerned with the application of scientific names to taxa, based on a particular classification scheme and in accordance with agreed international rules and conventions IUPAC nomenclature • is a system of naming chemical compounds and for describing the science of chemistry in general. It is maintained by the International Union of Pure and Applied Chemistry. Ionic Binary Compounds: IUPAC Naming • Metal non-metal -ide Ionic Binary compounds • A binary compound is one that only contains two elements in the compound. It may have multiple atoms of each element but can only have two elements. • An ionic binary compound is a compound contains one metal and one non-metal. Either element may have multiple atoms but there can only be the two elements involved. Ionic Binary Compounds: IUPAC Naming • Consists of two types of monoatomic ions 1. The metal ion is always written first and retains its whole name 2. The non-metal is written second and has a slight change, the ending (suffix) is changed to –ide • Do not write ones (Ex Na1Cl1) and if both elements have the same number reduce to lowest terms (Ca2O2 = CaO) Example Example: • Na + Cl • Use the cross over method Na+ Cl- = NaCl • sodium + chlorine • The metal name is written in full and the non-metal has the –ide suffix added to it. • Sodium chloride • Binary compounds can be made up of more than two ions, provided that there are only two types of elements. Example: Al2O3 • STUDY TIP: All metals in group 1 and 2 follow periodic law. Check all the others metals when naming. Practice • Work on the problems given on the sheet. Ionic Multivalent Binary Compounds • A multivalent compound is one that may have varied numbers of electrons in its valence shell. This occurs with elements that fall outside of the representative elements. The transition metals are elements that commonly have multiple valence shell electrons. • This means that they can form compounds in various proportions. • Example: Copper + Oxygen • Copper and oxygen could have two different formulas with two completely different properties. • CuO and Cu2O • In order to differentiate the two compounds we must use a different method to name them to avoid confusion. Ionic Multivalent Binary Compounds: IUPAC Naming • • Metal (charge) non-metal-ide Ionic Multivalent Binary Compounds: IUPAC Naming • Same as Ionic Binary but it indicates the metals charge 1. List the metal name first 2. After the metal name indicate the ion charge in brackets using roman numerals. 3. The non-metal has -ide suffix added. • Do not write 1’s and reduce when possible • ONLY SHOW ROMAN NUMERALS FOR MULTIVALENT COMPOUNDS • Not all transition metals are multivalent and thus do not have roman numerals Example • SnO2 Sn2+ O- Sn4+O2- tin (IV) oxide • SnO Sn+ O- Sn2+O2- tin (II) oxide • Work on the practice questions, • They are homework • The Worksheet will be handed in