Nomenclature Chapter 5 1

Classifying Binary Compounds Compounds containing a metal and a nonmetal are binary ionic Type I and II Compounds containing two nonmetals Type III Compounds containing H and a nonmetal = Acids 4

Type III - Binary Compounds of 2 Nonmetals These binary compounds always start with a nonmetal or a metalloid. That’s the easiest way to identify them. They will contain no metals! Name first element in formula first, use the full name of the element Name the second element in the formula as if it were an anion However, remember these compounds do not contain ions, so DO NOT USE THE CRISS-CROSS METHOD!!! 10

Type III Binary Molecular Compounds Use a prefix in front of each name to indicate the number of atoms Never use the prefix mono- on the first element Prefixes: 1-mono, 2-di, 3-tri, 4-tetra,5-penta, 6-hexa, 7-hepta, 8-octa, 9-nona, 10-deca, 11-undeca, 12-dodeca. To write the formula for binary molecular compounds, write the number next to the compound if there is a prefix, if not just write the symbol itself.

Binary Molecular Compounds Examples Naming Compounds SiF2 - silicon difluoride C3Cl9 - tricarbon nonachloride S4I7 – tetrasilicon heptaiodide P5O10 – pentaphosphorus octoxide Writing Formulas Nitrogen trichloride – NCl3 Triphosphorus pentoxide - P3O5 Hexasulfur monofluoride - S6F Diselenium pentabromide – Se2Br5

Metal Cations Type I Type II Metals that can only have one possible charge Determine charge by position on the Periodic Table Type II Metals that can have more than one possible charge Determine metal cation’s charge from the charge on anion 6

Type II Binary Ionic Compounds Contain Metal Cation + Nonmetal Anion Metal listed first in formula & name Name metal cation first, name nonmetal anion second Metal cation name is the metal name followed by a Roman Numeral in parentheses to indicate its charge Determine charge from anion charge Common Type II cations in Table 5.2 (page 128 or on Week #3 Ions & Symbols List) Nonmetal anion named by changing the ending on the nonmetal name to -ide 8

Naming Binary Type II Compounds Cu+1 and N-3 Hg+2 and O-2 Cr+3 and P-3 Sn+4 and Cl-1 Ni+4 and S-2 Iron (III) phosphide Manganese (II) fluoride Gold (I) telluride Lead (IV) bromide Cobalt (III) arsenide

Ionic Compounds Sometimes you can use the reverse of the criss-cross method to determine the charges for the transition metals. When naming compounds, you do not need to tell how many atoms of each ion are present.

Naming Ionic Compounds Examples Au2S MnO Fe3N2 CuCl2 NiS2 Cr3P2 PbF4 HgI

Figure 5.1: A flow chart for naming binary compounds.

Ionic Compounds Ternary ionic compounds – contain atoms of three or more different elements, usually a polyatomic ion. Writing the formulas for ternary compounds is done in the same way as binary compounds. The polyatomic ions stays together though.

Ionic Compounds When you need more than one polyatomic ion in your formula, put parentheses around the ion, and how many of them you need outside the parentheses as a subscript. NEVER MOVE SUBSCRIPTS OF THE IONS, ONLY THE CHARGES!!!

Writing Formulas for Ternary Ionic Compound Examples Calcium sulfate Ca+2 and SO4-2 Sodium chlorate Na+1 and ClO3-1 Magnesium hydroxide Mg+2 and OH-1 Potassium phosphate K+1 and PO4-3 Iron (III) carbonate Fe+3 and CO3-2 Tin (IV) chromate Sn+4 and CrO4-2 Nickel (II) dihydrogen phosphate Ni+2 and H2PO4-1 Chromium (III) sulfate Cr+3 and SO4-2 Copper (II) acetate Cu+2 and C2H3O2-1 Iron (II) permanganate Fe+2 and MnO4-1

Ionic Compounds When naming ternary compounds, name the cation (first symbol in the formula unless it is ammonium, NH4+1) first, and then the rest of the formula, which will only have one name, unless it contains hydrogen.

Naming Ternary Ionic Compounds Ca(NO3)2 KClO3 BaSO3 AlPO4 CuOH Ni3(PO3)4 Fe(CN)2 Mn(HCO3)3 Au2CO3 Cr2HPO4

Acids Naming & Writing Formulas for Acids All acids begin with a hydrogen, and are neutral compounds. In all acids, the cation is the hydrogen ion, H+1. Anions change their endings when they become acids.

Acids -ide ions become hydro root ic acid Ex: chloride becomes hydrochloric acid -ate ions become root ic acid Ex: nitrate becomes nitric acid -ite ions become root ous acid Ex: chlorite becomes chlorous acid

Acids Naming & Formula Writing Examples Writing Formulas for Acids Sulfuric acid Hydroarsenic acid Perchloric acid Hypoiodous acid Naming Acids H3PO3 HI HCN H2C4H4O6

Hydrates Hydrates are when you have a certain number of water molecules attached to a compound (usually an ionic compound) The number of water molecules is shown after the formula for a compound and separated from the remainder of the compound by a dot.

Hydrates Use the same prefixes as you did when naming binary molecular compounds to tell how many water molecules are present in a hydrate (1 = mono, 2 = di, …) An anhydrous compound is one that contains no water molecules.

Hydrate Examples CuSO4 . 5H2O Mg(NO3)2 . 3 H2O Barium chloride dihydrate Ammonium acetate octahydrate

Basic Organic Compounds You will need to know the names of the first 10 alkanes (hydrocarbons containing only single bonds). The generic formula of these alkanes is: CnH2n+2

Basic Organic Compounds Methane – CH4 Ethane – C2H6 Propane – C3H8 Butane – C4H10 Pentane – C5H12 Hexane - C6H14 Heptane - C7H16 Octane - C8H18 Nonane - C9H20 Decane - C10H22