Chapter 8 Chemical Nomenclature

Classification of Compounds Chemical nomenclature IUPAC rules Generalizations for ionic vs. molecular compounds Metal with nonmetals Nonmetal with other nonmetals NH4+ exception Metalloids

Types of Binary Ionic Compounds Fixed-charge Variable-charge Figure 8.1 shows fixed-charge metallic ions Table 8.1 shows more common variable-charge metals. Vast majority of metals are variable-charge metals.

Nomenclature for Binary Ionic Compounds Metal ions Fixed-charge Variable-charge Nonmetal ions

Nomenclature for Binary Ionic Compounds (cont’d) Fixed-charge binary ionic compounds KCl MgO Li2S ZnBr2 Variable-charge binary ionic compounds CuO Cu2O FeO

Nomenclature for Binary Ionic Compounds (cont’d) Variable-charge binary ionic compounds – (-ic, -ous) system Metal has two common charges Iron (III) chloride Copper (I) fluoride Stannic bromide Fe203 Tin (II) fluoride Table 8.3 – comparison of IUPAC and Old System Names for Selected Metal Ions – note that Latin names for metals are used.

Nomenclature for Ionic Compounds Containing Polyatomic Ions Common polyatomic ions charge 4 exceptions with –ide suffix -ate vs. –ite suffix ions with and without H replacement of O with S (thio- prefix) Names of ionic compounds Table 8.4 – learn contents

Naming Polyatomic-Ion-Containing Compounds Na3PO4 Fe(NO3)3 Cu2SO4 NH4CN FeCO3 Sn(OH)2

Nomenclature for Binary Molecular Compounds Two nonmetallic elements Nomenclature Less electronegative element first 2nd element take suffix –ide Numerical prefix indicates the number of atoms of each nonmetal Table 8.5 – Greek Numerical Prefixes from 1 to 10

Naming Binary Molecular Compounds N2O3 PF3 S4N4 SiCl4 Na2CO3 – disodium carbon trioxide MgClx Problem 8.129 S20 P4S6 5th bullet – ionic 6th – what’s “x” Carbon dioxide Table 8.6 – Binary Molecular Compounds with Common Names

Nomenclature for Acids Hydrogen-containing molecular compound Acids: HCl, H2S, HNO3, H2SO4 Non-acids: NH3, CH4, SiH4 H2O, not considered an acid -ide rule the prefix hydro- the stem of the name of the negative ion the suffix –ic the word acid Many hydrogen-containing molecular compounds dissolve in water to give solutions with properties markedly different from those of the compounds that were dissolved. These solutions are called acids. An acid is a hydrogen-containing molecular compound whose molecules yield hydrogen ions (H+) when dissolved in water. HCl – hydrochloric acid HCN – hydrocyanic acid

Nomenclature for Acids (cont’d) -ate rule negative ion less the –ate ending the suffix –ic the word acid -ite rule negative ion less the –ite ending the suffix –ous The word acid ate rule: HNO3 - nitrate less ate, plus ic; then add acid. HClO4 – perchlorate, less ate, plus ic, add acid: perchloric acid -ite rule: HNO2 nitrous acid, HClO hypochlorous acid

Naming Acids H2SO4 Sulfuric acid HCl (g) Hydrogen chloride gas HNO3 Nitric acid HI Hydroiodic acid

Naming Acids - cont’d HCN Hydrocyanic acid H3PO4 Phosphoric acid H3PO3 Phosphorous acid

Naming Acids – cont’d Chloric acid HClO3 Chlorous acid HClO2 Nitrous acid HNO2

Naming Acids – cont’d Hydrosulfuric acid H2S Sulfuric acid H2SO4 Carbonic acid H2CO3

Summary of Nomenclature Rules Ionic or molecular If ionic, binary or polyatomic If molecular, acid or nonacid