1 CHEM 105 Naming Inorganic Binary Compounds

2 Chemical nomenclature is the system of names that chemists use to identify compounds. Two classes of names exist: common names and systematic names.

3 –They are not based on the composition of the compound. –They are based on an outstanding chemical or physical property. Chemists prefer systematic names. –Systematic names precisely identify the chemical composition of the compound. –The present system of inorganic chemical nomenclature was devised by the International Union of Pure and Applied Chemistry (IUPAC). Common names are arbitrary names.

4

5 Elements and Ions

6 The formula for most elements is the symbol of the element. SodiumNa PotassiumK ZincZn ArgonAr MercuryHg LeadPb CalciumCa

7 Hydrogen moleculeH 2 Nitrogen moleculeN 2 Oxygen moleculeO 2 Fluorine molecule F 2 Chlorine moleculeCl 2 Bromine moleculeBr 2 Iodine molecule I 2 These 7 elements are found in nature as diatomic molecules.

8 Sulfur moleculeS 8 Phosphorous moleculeP 4 Two elements are commonly polyatomic.

9Ions

10 A positively charged ion 1.is formed when an atom loses electrons. 2.is called an anion. 3.is usually a nonmetallic element. 4.has more electrons than protons.

11 → remove e - neutral atom A charged particle known as an ion can be produced by adding or removing one or more electrons from a neutral atom. If one or more electrons are removed from a neutral atom a positive ion is formed. A positive ion is called a cation.

12 Na  Na + + e - Ca  Ca e - Al  Al e - Positive Ion Formation: Loss of Electrons From a Neutral Atom

13 Naming Cations

14 Cations are named the same as their parent atoms plus the word ion.

15 Atom Cation Name of Cation sodium (Na) Na + sodium ion

16 Atom Cation Name of Cation calcium (Ca) Ca 2+ calcium ion

17 → neutral atom A charged particle known as an ion can be produced by adding or removing one or more electrons from a neutral atom. If one or more electrons are added to a neutral atom a negative ion is formed. A negative ion is called an anion. add e -

18 Naming Anions

19 An anion consisting of one element has the stem of the parent element and an –ide ending

20 Atom Anion Name of Anion fluorine (F) F-F- fluoride ion stem

21 Atom Anion Name of Anion chlorine (Cl) Cl - chloride ion stem

22 Atom Anion Name of Anion bromine (Br) Br - bromide ion stem

23 Binary compounds contain only two different elements.

24 Compounds between nonmetals are molecular or covalent.

25 A Greek prefix is placed before the name of each element to indicate the number of atoms of the element that are present and the suffix –ide is place at the end.

26 di = 2 tri = 3 tetra = 4 penta = 5 hexa = 6 hepta = 7 octa = 8 nona = 9 deca = 10 mono = 1 Mono is rarely used when naming the first element.

27Examples

28 N2O3N2O3 dinitrogen trioxide indicates two nitrogen atoms indicates three oxygen atoms

29 Cl 2 O 7 dichlorine heptaoxide indicates two chlorine atoms indicates seven oxygen atoms

30 Step 1 There are 2 elements present. The compound is binary. Phosphorous and chlorine are nonmetals so the rules for naming binary compounds of 2 nonmetals apply. Phosphorous is named first. Therefore the compound is a chloride. Determine the Name of PCl 5

31 Step 2 No prefix is needed for phosphorous because each molecule of PCl 5 has only one phosphorous atom. The prefix penta- is used with chloride because there are 5 chlorine atoms present in one molecule. Step 3 The name is phosphorous pentachloride. Determine the Name of PCl 5

32Examples

33 dichlorine trioxide Cl 2 O 3

34 dinitrogen trioxide N2O3N2O3

35 carbon tetrachloride CCl 4

36 carbon monoxide CO

37 carbon dioxide Name CO 2

38 phosphorous triiodide Name PI 3

39 Binary ionic compounds consist of a metal combined with a non-metal.

40 How does a covalent bond differ from an ionic bond? 1.An ionic bond is the transfer of electrons and a covalent bond is a sharing of electrons. 2.An ionic bond involves 2 electrons and a covalent bond involves 4 electrons. 3.An ionic bond is usually between two metals and a covalent bond is usually between two nonmetals. 4.Ionic bonds are usually found in acids and covalent bonds are usually found in bases.

41 A. Binary Ionic Compounds Containing a Metal Forming Only One Type of Cation

42 The chemical name is composed of the name of the metal followed by the name of the nonmetal which has been modified to an identifying stem plus the suffix –ide. Using this system the number of atoms of each element present is not expressed in the name.

43 Name of Metal + Stem of Nonmetal plus -ide ending

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45 Step 1 From the formula it is a two- element compound and follows the rules for binary compounds. Name the Compound CaF 2

46 Name the Compound CaF 2 Step 2 The compound is composed of Ca, a metal and F, a nonmetal. Ca forms only a +2 cation. Thus, call the positive part of the compound calcium.

47 Step 3 Modify the name of the second element to the stem fluor- and add the binary ending –ide to form the name of the negative part, fluoride. Name the Compound CaF 2

48 Step 4 The name of the compound is therefore calcium fluoride. Name the Compound CaF 2

49Examples

50 Compound Name sodium chloride NaCl nonmetal stem name of metal

51 Compound Name magnesium chloride MgCl 2 nonmetal stem name of metal

52 Compound Name potassium oxide K2OK2O nonmetal stem name of metal

53 Compound Name sodium phosphide Na 3 P nonmetal stem name of metal

54 Monatomic anions are named with the suffix 1.-ate. 2.-ite. 3.-ide. 4.-ade.

55 B. Binary Ionic Compounds Containing a Metal That Can Form Two or More Types of Cations

56 The metals in the center of the periodic table (including the transition metals) often form more than one type of cation.

57 Each ion of iron forms a different compound with the same anion. Fe 2+ Fe 3+ FeS Fe 2 S 3

58 Stock System Lower Charge Higher Charge ElementFormulaNameFormulaName Copper Cu + copper (I) Cu 2+ copper (II) Iron Fe 2+ iron(II) Fe 3+ iron(III) Lead Pb 2+ lead (II) Pb 4+ lead(IV) Mercury Hg 2 2+ mercury(I) Hg 2+ mercury(II) Tin Sn 2+ Tin(II) Sn 4+ Tin (II) Stock System Higher Charge ElementFormulaNameFormulaName Lower Charge

59 IUPAC devised the Stock System of nomenclature to name compounds of metals that have more than one type of cation. Cation Charge Roman Numeral IIIIIIIVV In the Stock System the charge on the cation is designated by a Roman numeral placed in parentheses immediately following the name of the metal. The nonmetal name ends in -ide.

60 Ions are always formed by adding or removing electrons from an atom.

61 Name the Compound FeS Step 1 This compound follows the rules for a binary compound.

62 Step 2 It is a compound of Fe, a metal, and S, a nonmetal, and Fe is a transition metal that has more than one type of cation. Name the Compound FeS Step 2 In sulfides, the charge on S is –2. Therefore the charge on Fe must be +2, and the name of the positive part of the compound is iron (II).

63 Step 3 We have already determined that the name of the negative part of the compound will be sulfide. Name the Compound FeS

64 Step 4 The name of FeS is iron(II) sulfide. Name the Compound FeS

65 ion chargeion name SnBr 2 tin(II) bromide +2 bromidetin(II) SnBr 4 tin(IV) bromide +4 tin(IV)bromide compound name

66 ion chargeion name FeCl 2 iron(II) chloride +2 chlorideiron(II) FeCl 3 iron(III) chloride +3 iron(III)chloride compound name

67 The Classical System

68 In the Classical System the name of the metal (usually the Latin name) is modified with the suffixes -ous and ic.

69 -ous lower charge - ic higher charge Metal name ends in nonmetal name ends in -ide

70 Examples

71 ion chargeion name FeCl 2 ferrous chloride +2 chlorideferrous FeCl 3 ferric chloride +3 ferricchloride compound name

72 ion chargeion name SnBr 2 stannous bromide +2 bromidestannous SnBr 4 stannic bromide +4 stannicbromide compound name

73 Lower Charge Higher Charge ElementFormulaNameFormulaName CopperCu + cuprousCu 2+ Cupric IronFe 2+ ferrousFe 3+ ferric LeadPb 2+ plumbousPb 4+ plumbic MercuryHg + mercurousHg 2+ mercuric TinSn 2+ stannousSn 4+ stannic Ion Names: Classical System

74 Acids Derived from Binary Compounds aka Hydrogen + nonmetal

75 Certain binary hydrogen compounds, when dissolved in water, form solutions that have acid properties. The aqueous solutions of these compounds are given acid names. The acid names are in addition to their –ide names. Hydrogen is typically the first element of a binary acid formula.

76 Acid Formation water binary hydrogen compound (not an acid). acid

77 Dissolved in water acid HCl (aq) Pure compound HCl -ide

78 To name binary acids write the symbol of hydrogen first. After hydrogen write the symbol of the second element. Place the prefix hydro- in front of the stem of the nonmetal name. Place the suffix -ic after the stem of the nonmetal name.

79Examples

80 HCl hydrogen chloride Pure Compound

81 HCl hydrochloric acid Dissolved in Water

82 HI hydrogen iodide Pure Compound

83 HI hydroiodic acid Dissolved in Water

84 H2SH2S hydrogen sulfide Pure Compound

85 H2SH2S hydrosulfuric acid Dissolved in Water

86 H 2 Se hydrogen selenide Pure Compound

87 H 2 Se hydroselenic acid Dissolved in Water

88 What is the name of the molecular substance PCl 5 ? 1.phosphorous chloride 2.monophosphorous pentachloride 3.phosphorous pentachloride 4.All of the above are suitable names.

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