Chemical Nomenclature Written by Y. Deng, J. Bazzi and D. Bandyopadhyay Produced by the Science Learning Center (SLC) University of Michigan -Dearborn 2013 What is Chemical Nomenclature? A set of rules to generate systematic names for chemical substances Language of chemistry Used by scientists, particularly chemists, to communicate and discuss the issues related to chemistry ? Purpose To introduce the systems of chemical nomenclature used to name inorganic compounds and to write chemical formulas of inorganic compounds. Inorganic vs. Organic Compounds Inorganic compounds are referred traditionally to those extracted from non-living things (e.g., rocks) and viewed as being synthesized by geological systems. Examples: calcium carbonate (a major compound found in rocks): CaCO3 Sodium chloride (a major compound found in table salt): NaCl Organic compounds, on the other hand, are referred traditionally to those found in living things (e.g., plants and animals) and mainly contain carbon-hydrogen chain and ring structures. Examples: Ethanol (one of the fermentation products of grapes): CH3CH2OH Caffeine (one of the components found in coffee beans): Specific Objectives: 1. Write correct chemical formulas for inorganic compounds. 2. Name inorganic compounds. 3. Determine the electric charges of ions involved in ionic compounds. Part I THE PERIODIC TABLE OF ELEMENTS AND SYMBOLS OF THE ELEMENTS The Periodic Table of the Elements is a tabular arrangement of the chemical elements, organized on the basis of their atomic numbers (i.e., the number of protons in their nuclei) and recurring chemical properties. There are 118 elements currently listed on the periodic table. About 90 elements are found in nature. The remaining ones have been produced artificially using high energy particle accelerators. Each element has its name and symbol. The symbol can be up to three letters. The first letter must be capitalized and the second and third, if any, are in a lower case. Examples: Name Nitrogen Chlorine Ununpentium Symbol N Cl Uup The symbols of the elements are derived from: English names hydrogen – H calcium– Ca phosphorus – P Latin names Ferrum (iron) – Fe Aurum (gold) – Au Chemical Symbols Derived from Their English Names Symbol English Name Symbol English Name H hydrogen S sulfur C carbon Cl chlorine N nitrogen Ca calcium O oxygen Mg magnesium F fluorine Mn manganese Al aluminum Co cobalt Si silicon Ni nickel P phosphorous Zn zinc Ba barium Cr chromium Chemical Symbols Derived from Their Latin Names Symbol English Name Latin Name Meaning Ag silver argentum silver Au gold aurum shining dawn Fe iron ferrum iron Hg mercury hydrargyrum liquid silver K potassium kalium potash silver Na sodium natrium soda Pb lead plumbum heavy Cu copper cuprum “from Cyprus” where the Romans found copper. The main group elements that must be memorized, indicated in green color for their symbols and names alkali metals 1 IA Noble gases 18 VIIIA alkaline earth metals halogens or 0 H Hydrogen 2 IIA 13 IIIA 14 IVA 15 VA 16 VIA 17 VIIA He Helium Li Lithium Be Beryllium B Boron C Carbon N Nitrogen O Oxygen F Fluorine Ne Neon Na Sodium Mg Magnesium Al Aluminum Si Silicon P Phosphorus S Sulfur Cl Chlorine Ar Argon Transition Metals K Potassium Ca Calcium Br Bromine Rb Rubidium Sr Strontium Sn Tin Cs Cesium Ba Barium Pb Lead I Iodine Xe Xenon The transition metal elements that must be memorized, indicated in red color of their symbols and names 4 IVB 5 VB 6 VIB 7 VIIB Ti Titanium V Vanadium Cr Chromium Mn Manganese 8 9 10 ←VIIIB→ Fe Iron Co Cobalt Ni Nickel 11 IB 12 IIB Cu Copper Zn Zinc Ag Silver Pt Platinum Au Gold Hg Mercury Exercise 1 Write names or symbols of the following elements. 1. 2. 3. 4. 5. 6. 7. Ca K Co Mn Cr Fe P 8 . tin 9. silicon 10. gold 11. copper 12. carbon 13. neon 14. bromine Part II NAMING BINARY IONIC COMPOUNDS (CONTAINING TWO DIFFERENT ELEMENTS) Naming Binary Ionic Compounds An ionic compound is a chemical compound in which ions are held together by the electrostatic forces between oppositely charged bodies. Usually, the positively charged portion consists of metal cations (e.g., Na+) and the negatively charged portion consists of anions (e.g., Cl-). Formation of An Ionic Compound e- Cl Na Na+ Cl- A sodium atom loses an electron to form a positive ion (cation): Na+. A chlorine atom gains an electron to form a negative ion (anion): Cl-. The cation and the anion are held together by the electrostatic forces (ionic bond) to form an ionic compound. Rules for Naming Binary Ionic Compounds 1. When naming cations, the name of the element is used. 2. When naming anions that are derived from an atom of the element, the name of the element is modified with the suffix –ide added. For example: Chlorine (Cl) is the name of the element. When a chlorine atom gains an electron, it becomes an anion, chloride (Cl-). 3. Write the symbol of the cation first, and then the symbol of the anion. NaCl Formation of Magnesium Chloride Cl Write the formula with the positive & negative charges balanced. e- Cl- Mg Mg2+ e- Cl Cl- Mg 2+ + 2 Cl- MgCl2 A subscript “2” is used to indicate number of chloride ion present in a magnesium chloride compound. Rules for Naming Binary Ionic Compounds (Continued) 4. Compounds are electrically neutral, thus the total number of cations and anions must be such that positive and negative charges balance to zero. MgCl2 5. The number of each ion present in the compound is designated by a subscript following its chemical symbols. For example, an aluminum oxide compound consists of 2 aluminum cation (Al3+) and 3 oxide anions (O2-). Al2O3 A modified periodic table useful for writing formulas for binary ionic compounds. The numbers in blue indicate the common charges of cations and anions after these atoms gain or lose electrons. 15 VA 16 VIA 17 VIIA 18 VIIIA 1 IA 2 IIA 13 IIIA 3 2 1 0 +1 +2 +3 1 H 2 He 3 Li 4 Be 7 N 8 O 9 F 10 Ne 11 Na 12 Mg 13 Al 15 P 16 S 17 Cl 18 Ar 19 K 20 Ca 31 Ga 35 Br 36 Kr 37 Rb 38 Sr 53 I 54 Xe 55 Cs 56 Ba Non-metals Transition Metal Elements Metals Examples of Binary Ionic Compounds Full Name Name of Cation Name of Anion Chemical Formula sodium chloride sodium (Na+) chloride (Cl-) NaCl lithium bromide lithium (Li+) bromide (Br-) LiBr calcium iodide calcium (Ca 2+) Iodide (I-) CaI2 aluminum sulfide aluminum (Al3+) sulfide (S2-) Al2S3 potassium oxide potassium (K+) oxide (O2-) K2O lithium hydride lithium (Li+) hydride (H-1) LiH barium nitride barium (Ba2+) nitride (N3-) Ba3N2 strontium phosphide strontium (Sr2+) phosphide (P3-) Sr3P2 Some metals can form cations with different charges. These cations can be named using two systems: (a) Stock System: The charges of cations can be described by using Roman numerals. Ex. Iron can form two cations: Fe2+ & Fe3+ FeCl2: iron(II) chloride FeCl3: iron(III) chloride (pronounce: iron-two chloride; iron-three chloride) (b) Classical system: Assign the ending “ous” to the cations with fewer positive charges and the ending “ic” to the cations with more positive charges Ex. Iron can form two cations: Fe2+ & Fe3+ FeCl2: ferrous chloride FeCl3: ferric chloride Naming of Cations Using the Classical and Stock Systems: Cations Names, Charges Element chromium, Cr cobalt, Co copper, Cu iron, Fe lead, Pb manganese, Mn mercury, Hg nickel, Ni tin, Sn chromium(II) (chromous) cobalt(II) (cobaltous) copper(I) (cuprous) iron(II) (ferrous) lead(II) (plumbous) manganese(II) (manganous) mercury(I) (mercurous) nickel(II) (nickelous) tin (II) (stannous) +2 +2 +1 +2 +2 +2 +1 +2 +2 chromium(III) (chromic) cobalt(III) (cobaltic) copper(II) (cupric) iron(III) (ferric) lead(IV) (plumbic) manganese(III) (manganic) mercury(II) (mercuric) nickel(III) (nickelic) tin(IV) (stannic) +3 +3 +2 +3 +4 +3 +2 +3 +4 Additional Examples of Binary Ionic Compounds Chemical Formula Name of Cation Name of Anion Name (Stock System) Name (Classical System) FeF2 (Fe2+) iron(II), ferrous fluoride (F-) iron(II) fluoride ferrous fluoride FeF3 (Fe3+) iron(III), ferric fluoride (F-) iron(III) fluoride ferric fluoride Cu2O (Cu+) copper(I), cuprous oxide (O2-) copper(I) oxide cuprous oxide CuO (Cu2+) copper(II), cupric oxide (O2-) copper(II) oxide cupric oxide PbBr2 (Pb2+) bromide (Br-) lead(II), plumbous lead(II) bromide plumbous bromide PbBr4 (Pb4+) lead(IV), plumbic lead(IV) bromide plumbic bromide bromide (Br-) Exercise 2 Give the names or formulas of the following binary ionic compounds. If a compound can be named by both the Stock and the Classical systems, provide both names. 1. CaO2 2. NaH 3. Mg3N2 4. FeI3 5. CuCl 6. CuCl2 7. Ba3P2 8. aluminum chloride 9. calcium phosphide 10. stannous oxide 11. ferric bromide 12. ferrous bromide 13. barium nitride 14. nickel(III) chloride Part III NAMING IONIC COMPOUNDS CONTAINING POLYATOMIC IONS Names of Some Oxo-Anions An oxo-anion usually contains two elements in which one of them must be oxygen. The oxo-anions of some elements (in blue) can have either a suffix -ate or -ite added to the root names of the elements. For example, SO42- and SO32- are oxo-anions of sulfur element. Their names are sulfate and sulfite, respectively. IIIA B BO33borate VIB Cr CrO42chromate Cr2O72dichromate VIIB Mn MnO42manganate MnO4permanganate IVA VA VIA VIIA C CO32carbonate N NO3nitrate {NO2-} {nitrite} O F Si SiO44silicate P PO43phosphate {PO33-} {phosphite} S SO42sulfate {SO32-} {sulfite} Cl ClO3chlorate {ClO2-} {chlorite} Br BrO3bromate I IO3iodate Names of Common Polyatomic Ions Formula of Ion Name of Ion Formula of Ion Name of ion Formula of Ion Name of Ion NO2- nitrite NO3- nitrate SCN- thiocyanate SO42- sulfate HSO4- hydrogen sulfate bisulfate BrO3- bromate SO32- sulfite HSO3- hydrogen sulfite bisulfite AsO33- arsenite CO32- carbonate HCO3- bicarbonate hydrogen carbonate AsO43- arsenate MnO4- permanganate CrO42- chromate Cr2O72- dichromate PO43- phosphate HPO42- hydrogen phosphate H2PO42- dihydrogen phosphate ClO2- chlorite ClO3- chlorate ClO4- perchlorate ClO- hypochlorite IO3- iodate IO4- periodate Names of Common Polyatomic Ions (cont.) Formula Ion NH4+ CN OH ammonium mercury(I) (mercurous) cyanide hydroxide O22 peroxide SCN thiocyanate C2H3O2 (or CH3COO-) acetate CHO2- (or HCOO-) formate C2O42- (or -OOC-COO-) oxalate Hg22+ Examples of Ionic Compounds with Polyatomic Ions Formula Name of Cation Name of Anion Stock System Classical System NiSO4 (Ni2+) nickel(II), nickelous sulfate(SO42-) nickel(II) sulfate nickelous sulfate Ni2(SO4)3 (Ni3+) nickel(III), nickelic sulfate(SO42-) nickel(III) sulfate nickelic sulfate (NH4)2HPO4 (NH4+), ammonium hydrogen phosphate(HPO42-) ammonium hydrogen phosphate ammonium hydrogen phosphate Al(CH3COO)3 Al3+, aluminum acetate(CH3COO -) aluminum acetate aluminum acetate Hg2(NO2)2 (Hg22+) mercury(I) mercurous nitrite(NO2-) mercury(I) nitrite mercurous nitrite Hg(NO2)2 (Hg2+) mercury(II) mercuric nitrite(NO2-) mercury(II) nitrite mercuric nitrite Exercise 3 Give the names or formulas of the following ionic compounds with polyatomic ions. If a compound can be named by both the Stock and the Classical systems, provide both names. 1. CaSO3 2. NaHCO3 3.Hg2(NO3)2 4. Hg(NO2)2 5. Cu(CH3COO)2 6. Ba(SCN)2 7. Na2Cr2O7 8. calcium phosphate 9. cuprous sulfite 10. ammonium nitrite 11. ferrous dihydrogen phosphate 12. barium cyanide 13. potassium permanganate 14. plumbous carbonate Part IV NAMING ACIDS AND BASES An acid is a substance that ionizes in water to produce hydrogen ions (H+). A base is a substance that ionizes in water to produce hydroxide ions (OH-). A. Acids without oxygen atoms The following compounds are named depending on whether they are present as pure substances or are dissolved in water to form aqueous solutions . Formula Pure Substance Aqueous Solution HCl hydrogen chloride hydrochloric acid HBr hydrogen bromide hydrobromic acid HI hydrogen iodide hydroiodic acid H2S hydrogen sulfide hydrosulfuric acid HCN hydrogen cyanide hydrocyanic acid B. Common oxo-anions and their corresponding oxo-acids. Element Oxo-Anion Oxo-Acid boron BO33 borate H3BO3 boric acid nitrogen NO3 nitrate HNO3 nitric acid PO43 phosphate H3PO4 phosphoric acid PO33 phosphite H3PO3 phosphorous acid SO42 sulfate H2SO4 sulfuric acid SO32 sulfite H2SO3 sulfurous acid ClO hypochlorite HClO hypochlorous acid ClO2 chlorite HClO2 chlorous acid ClO3 chlorate HClO3 chloric acid ClO4 perchlorate HClO4 perchloric acid bromine BrO3 bromate HBrO3 bromic acid iodine IO3 iodate HIO3 iodic acid phosphorus sulfur chlorine C. Common organic acids Formula Name HCOOH (CH2O2) formic acid CH3COOH (C2H4O2) acetic acid HOOCCOOH (C2H2O4) oxalic acid D. Bases Formula Name Formula Name NaOH sodium hydroxide LiOH lithium hydroxide KOH potassium hydroxide Sr(OH)2 strontium hydroxide Mg(OH)2 magnesium hydroxide Ca(OH)2 calcium hydroxide Ba(OH)2 barium hydroxide AgOH silver hydroxide Zn(OH)2 zinc hydroxide Al(OH)3 aluminum hydroxide Hg2(OH)2 mercury(I) hydroxide mercurous hydroxide Hg(OH)2 mercury(II) hydroxide mercuric hydroxide CuOH copper(I) hydroxide cuprous hydroxide Cu(OH)2 copper(II) hydroxide cupric hydroxide Ni(OH)2 nickel(II) hydroxide nickelous hydroxide Ni(OH)3 nickel(III) hydroxide nickelic hydroxide Co(OH)2 cobalt(II) hydroxide cobaltous hydroxide Co(OH)3 cobalt(III) hydroxide cobaltic hydroxide Pb(OH)2 lead(II) hydroxide plumbous hydroxide Cr(OH)3 chromium(III) hydroxide chromic hydroxide Exercise 4 Give the names or formulas of the following acids and bases. If an acid or a base can be named by both the Stock and the Classical systems, provide both names. 1. HF (aqueous solution) 2. H2SO3 3. H2CO3 4. H2S (pure substance) 5. Hg2(OH)2 6. Fe(OH)2 7. H3PO4 8. nitric acid 9. aluminum hydroxide 10. ferric hydroxide 11. cuprous hydroxide 12. hydrocyanic acid 13. nitrous acid 14. sulfuric acid Part V NAMING HYDRATES Hydrates – compounds that have a specific number of water molecules attached to them. Examples: (1) BaCl2·2H2O (2) CuSO4·5H2O (3) MgSO4·7 H2O The First Ten Greek Prefixes Greek Prefix Number monoditritetrapentahexaheptaoctanonadeca- 1 2 3 4 5 6 7 8 9 10 Examples of Hydrates and Their Names The Greek prefixes are used to indicate the number of water molecules in hydrates. (1) BaCl2·2H2O Name: barium chloride dihydrate (2) CuSO4·5H2O Name : copper(II) sulfate pentahydrate (Stock System) Or cupric sulfate pentahydrate (Classical System) (3) MgSO4·7 H2O Name: magnesium sulfate heptahydrate Exercise 5 Give the names or formulas for the following hydrates. If a hydrate can be named by both the Stock and the Classical systems, provide both names. (1) LiCl·H2O (2) (3) (4) (5) MgSO4·7H2O CoCl2·6H2O CuSO4·5H2O Na2SO4∙10H2O (6) barium chloride dihydrate (7) sodium carbonate decahydrate (8) ferrous sulfate hexahydrate (9) strontium nitrate tetrahydrate (10) manganese(II) nitrate tetrahydrate Part VI NAMING BINARY MOLECULAR COMPOUNDS (CONTAINING TWO ELEMENTS, BUT DON’T CONTAIN CATIONS AND ANIONS) Rules for Naming Binary Molecular Compounds Examples of binary molecular compounds: CO2, CCl4 1.When naming the first element, the name of the element is used. 2.Then name the second element by taking the first part of the element name and adding the suffix “ide”. 3.Use Greek prefixes to denote the number of atoms of each element present. 4.The prefix “mono” can be omitted for the first element. 5.For oxides, the ending “a” in the prefix is sometimes omitted. Examples CO: carbon monoxide (not monocarbon monoxide) CO2: carbon dioxide SO3: sulfur trioxide N2O4: dinitrogen tetroxide (not tetraoxide) PCl5: phosphorus pentachloride S2F10: disulfur decaflouride An exception to the use of Greek prefixes involves molecular compounds containing hydrogen Traditionally, many of these compounds are called either by their common names or by names that do not specifically indicate the number of H atoms present. Examples: CH4 - methane; NH3 – ammonia; PH3 – phosphine H2O- water; H2S – hydrogen sulfide; SiH4 -silane Exercise 6 Give the names or formulas for the following binary molecular compounds. 1. NO 8. dinitrogen monoxide 2. SO2 9. boron trichloride 3. Cl2O7 10. diarsenic pentoxide 4. PBr3 11. sulfur hexachloride 5. SF6 12. nitrogen triiodide 6. P2O5 13. carbon tetra bromide 7. CCl4 14. diphosphorus pentoxide Acknowledgements The authors would like to thank Ali Bazzi, Ogie Stewart and Ruixiao Zuo for their valuable comments and suggestions that were of great help in preparing and improving this module. The authors would like to thank Annette Sieg, Assistant Director of SLC, as well as the SLC staff for their help and technical support. Exercise 1 – Key Write names or symbols of the following elements 1. 2. 3. 4. 5. 6. 7. Ca K Co Mn Cr Fe P calcium potassium cobalt manganese chromium iron phosphorus 8 . tin 9. silicon 10. gold 11. copper 12. carbon 13. neon 14. bromine Sn Si Au Cu C Ne Br Exercise 2 - Key Give the names or formulas of the following binary ionic compounds. If a compound can be named by both the Stock and the Classical systems, provide both names. 1. CaO2 2. NaH 3. Mg3N2 4. FeI3 5. CuCl 6. CuCl2 7. Ba3P2 8. aluminum chloride 9. Calcium phosphide 10. Stannous oxide 11. Ferric bromide 12. Ferrous bromide 13. Barium nitride 14. Nickel (III) chloride calcium peroxide sodium hydride magnesium nitride ferric/iron(III) iodide cuprous/copper(I) chloride cupric/copper(II) chloride barium phosphide AlCl3 Ca3P2 SnO FeBr3 FeBr2 Ba3N2 NiCl3 Exercise 3 - Key Give the names or formulas of the following ionic compounds with polyatomic ions. If a compound can be named by both the Stock and the Classical systems, provide both names. 1. CaSO3 2. NaHCO3 3.Hg2(NO3)2 4. Hg(NO2)2 5. Cu(CH3COO)2 6. Ba(SCN)2 7. Na2Cr2O7 8. calcium phosphate 9. cuprous sulfite 10. ammonium nitrite 11. ferrous dihydrogen phosphate 12. barium cyanide 13. potassium permanganate 14. plumbous carbonate calcium sulfite sodium hydrogen carbonate or sodium bicarbonate mercurous/mercury(I) nitrate mercuric/mercury(II) nitrite cupric/copper(II) acetate barium thiocyanate sodium dichromate Ca3(PO4)2 Cu2SO3 NH4NO2 Fe(H2PO4)2 Ba(CN)2 KMnO4 PbCO3 Exercise 4 - Key Give the names or formulas of the following acids and bases. If an acid or a base can be named by both the Stock and the Classical systems, provide both names. 1. HF (aqueous solution) 2. H2SO3 3. H2CO3 4. H2S (pure substance) 5. Hg2(OH)2 6. Fe(OH)2 7. H3PO4 8. nitric acid 9. Aluminum hydroxide 10. Ferric hydroxide 11. Cuprous hydroxide 12. Hydrocyanic acid 13. Nitrous acid 14. Sulfuric acid hydrofluoric acid sulfurous acid carbonic acid hydrogen sulfide mercurous/mercury(I) hydroxide ferrous/iron (II) hydroxide phosphoric acid HNO3 Al(OH)3 Fe(OH)3 CuOH HCN HNO2 H2SO4 Exercise 5 - Key Give the names or formulas for the following hydrates. If a hydrate can be named by both the Stock and the Classical systems, provide both names. (1) LiCl·H2O lithium chloride monohydrate (2) MgSO4·7H2O magnesium sulfate heptahydrate (3) CoCl2·6H2O cobaltous/cobalt (II) chloride hexahydrate (4) CuSO4·5H2O cupric/copper (II) sulfate pentahydrate (5) Na2SO4∙10H2O sodium sulfate decahydrate (6) barium chloride dihydrate BaCl2·2H2O (7) sodium carbonate decahydrate Na2CO3·10H2O (8) ferrous sulfate hexahydrate FeSO4·6H2O (9) Strontium nitrate tetrahydrate Sr(NO3)2·4H2O (10) manganese (II) nitrate tetrahydrate Mn(NO3)2·4H2O Exercise 6 - Key Give the names or formulas for the following binary molecular compounds. 1. NO nitrogen monoxide 8. dinitrogen monoxide N2O 2. SO2 sulfur dioxide 9. boron trichloride BCl3 3. Cl2O7 dichlorine heptoxide 10. diarsenic pentoxide Ar2O5 4. PBr3 phosophorus tribromide 11. sulfur hexachloride SCl6 5. SF6 sulfur hexafluoride 12. nitrogen triiodide NI3 6. P2O5 diphosphorus pentoxide 13. carbon tetrabromide CBr4 7. CCl4 carbon tetrachloride 14. diphosphorus pentoxide P 2 O5