-Periodic-Naming-and-Formula-Writing.ppt
- 2. 2 Chapter Outline 6.1 Common and Systematic Names 6.2 Elements and Ions 6.3 Writing Formulas from Names of Compounds 6.4 Binary Compounds 6.5 Naming Compounds Containing Polyatomic Ions 6.6 Acids
- 3. 3 Common and Common and Systematic Names Systematic Names
- 4. 4 Chemical nomenclature is the system of names that chemists use to identify compounds. Two classes of names exist: common names and systematic names.
- 5. 5 – 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.
- 6. 6
- 7. 7 Elements and Ions Elements and Ions
- 8. 8 The formula for most elements is the symbol of the element. Sodium Na Potassium K Zinc Zn Argon Ar Mercury Hg Lead Pb Calcium Ca
- 9. 9 Hydrogen H2 Nitrogen N2 Oxygen O2 Fluorine F2 Chlorine Cl2 Bromine Br2 Iodine I2 These 7 elements are found in nature as diatomic molecules.
- 10. 10 Sulfur S8 Phosphorous P4 Two elements are commonly polyatomic.
- 11. 11 Ions Ions
- 12. 12 → 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.
- 13. 13 Na Na+ + e- Ca Ca2+ + 2e- Al Al3+ + 3e- Positive Ion Formation: Loss of Electrons From a Neutral Atom
- 15. 15 Cations are named the same as their parent atoms
- 21. 21 → 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-
- 23. 23 An anion consisting of one element has the stem of the parent element and an – ide ending
- 24. 24 Atom Anion Name of Anion fluorine (F) F- fluoride ion stem
- 26. 26 Atom Anion Name of Anion bromine (Br) Br- bromide ion stem
- 27. 27 Atom Anion Name of Anion nitrogen (N) N3- nitride ion stem
- 29. 29 Atom Anion Name of Anion oxygen (O) O2- oxide ion stem
- 30. 30 Ions are always formed by adding or removing electrons from an atom.
- 31. 31 Most often ions are formed when metals combine with nonmetals.
- 32. 32 The charge on an ion can be predicted from its position in the periodic table.
- 33. 33 elements of Group IIA have a +2 charge elements of Group IA have a +1 charge elements of Group VA have a -3 charge elements of Group VIA have a -2 charge elements of Group VIIA have a -1 charge
- 34. 34 Writing Formulas From Writing Formulas From Names of Compounds Names of Compounds
- 35. 35 A chemical formula is a shorthand way of writing the name of a compound. It is composed of the symbols of the elements and the number of atoms each element is present in the compound. The number of atoms of an element is written as a subscript.
- 36. Guidelines in writing the formulas of inorganic compounds: 1. Represent by symbols the fragments of the compound in the sequence that they occur in the given name. In most cases, the positive fragment (cation) comes first before the negative fragment (anion). Enclose the radicals in parenthesis. A radical is a group of elements that behaves as a unit with a charge that can either be a positive or negative. Refer to the list of common ions and their charges. 36
- 37. Example: Sodium chloride Na+ Cl- Aluminum oxide Al+3 O-2 Plumbic carbonate Pb+4 (CO3)-2 Calcium sulfate Ca+2 (SO4)-2 37
- 38. Guidelines in writing the formulas of inorganic compounds: 2. Cross indicate (crisscross) the charge as subscript (exclude the signs). In cases where the sum of the positive and negative charges is equal to zero, cross indication is not necessary. 38
- 39. Example: Sodium chloride Na+ Cl- NaCl Aluminum oxide Al+3 O-2 Al2O3 Plumbic carbonate Pb+4 (CO3)-2 Pb2(CO3)4 Calcium sulfate Ca+2 (SO4)-2 CaSO4 39
- 40. Guidelines in writing the formulas of inorganic compounds: 3. Observe the following: •In the final form, omit writing “1” if it is the subscript. •Reduce the subscript derived from cross indication into the smallest whole number. However, do not change the subscripts which appear in the radical(s). •Eliminate the parenthesis of the radicals when the subscript is “1”. 40
- 41. Example: Mg+2 Cl- --- Mg1Cl2 --- MgCl2 Pb+4 (CO3)-2 --- Pb2(CO3)4 --- Pb(CO3)2 Na+1 (S2O3)-2 --- Na2(S2O3)1 --- Na2S2O3 41
- 42. Guidelines in writing the formulas of inorganic compounds: 4. In some cases, two nonmetallic elements combine to form more than one kind of compounds. Examples of nonmetallic elements are carbon, sulfur, oxygen, nitrogen, chlorine, etc. These compounds are named with different prefixes to designate the number of atoms of one element that combine. If the prefix ends in a or o and the word that follows starts with a or o, drop the last vowel of the prefix. 42
- 44. 44 A Greek prefix is placed before the name of each element to indicate the number of atoms of the element that are present.
- 45. 45 • 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.
- 47. 47 N2O3 dinitrogen trioxide indicates two nitrogen atoms indicates three oxygen atoms
- 48. 48 PCl5 phosphorous pentachloride indicates one phosphorous atom indicates five chlorine atoms
- 49. 49 Cl2O7 dichlorine heptoxide indicates two chlorine atoms indicates seven oxygen atoms
- 50. 50 CO carbon monoxide Carbon dioxide CO2
- 51. 51 Nomenclature of Nomenclature of Inorganic Compounds Inorganic Compounds
- 52. Inorganic compounds are classified into oxides, bases, acids, and salts. Each class is distinguished from the others by their chemical formulas (composition), properties, and names. 52
- 53. Oxides The oxides are binary compounds (two elements) consisting of oxygen which is the anion and another element which may be a metal or a nonmetal. Thus, oxides are either metallic or nonmetallic. The name of a metallic oxide consists of the name of the cation followed by the term “oxide” 53
- 54. Examples Aluminum oxide Al2O3 Ferric oxide Fe2O3 54
- 55. Oxides In naming nonmetallic oxides, refer to #4. guidelines in writing the formula of inorganic compound. 55
- 56. Bases The inorganic bases are compounds of a metallic element with one or more hydroxyl (OH- ) groups. The name of a base consists of the name of the cation followed by the term “hydroxide” 56
- 57. Examples Ferrous hydroxide Fe(OH)2 Aluminum hydroxide Al(OH)3 57
- 58. Acids The inorganic acids are those compounds consisting of hydrogen and a negative ion (except O-2 ) or a negative radical whose water solution changes the color of litmus paper from blue to red. There are two kinds of inorganic acids: binary acid and ternary acid. 58
- 59. Binary Acids A binary acid is one in which the H is combined with a nonmetal such as Cl, Br, S, etc. Its name consists of prefix “hydro” connected to the root word of the nonmetal with the suffix “ic” and the word “acid”. Sulfur is an exception to the rule where its full name is used. •General formula: hydro root word ic acid 59
- 60. Examples HCl hydrochloric acid H2S hydrosulfuric acid 60
- 61. Ternary Acids A ternary acid is composed of three elements: hydrogen, a nonmetal, and oxygen. The nonmetal and oxygen, as a group, is called a radical and carries a negative charge. 61
- 62. Ternary Acids Name of Radical Name of Acid hypo______ite ______ite ______ate per______ate hypo__________ous acid __________ous acid __________ic acid per_________ ic acid 62
- 63. Examples Radical Acid Name Acid Formula Hypochlorite ClO- Hypochlorous acid HClO Chlorite ClO2 - Chlorous acid HClO2 Chlorate ClO3 - Chloric acid HClO3 Perchlorate ClO4 - Perchloric acid HClO4 63
- 64. Salts The salts are compounds consisting of a metal combined with a nonmetal or a negative radical except OH- . They are formed by the reaction between a base an acid which is called neutralization reaction. The cation comes from the base while the anion comes from the acid. 64
- 65. Salts NaOH + HCl NaCl + HOH base acid salt water 65
- 66. 66 A chemical compound must have a net charge of zero.
- 67. 67 If the compound contains ions, then the charges on all of the ions must add to zero.
- 68. 68 The Stock System The Stock System
- 69. 69 The metals in the center of the periodic table (including the transition metals) often form more than one type of cation.
- 70. 70 Each ion of iron forms a different compound with the same anion. Fe2+ Fe3+ FeS Fe2S3
- 71. 71 IUPAC devised the Stock System of nomenclature to name compounds of metals that have more than one type of cation. Cation Charge +1 +2 +3 +4 +5 Roman Numeral I II III IV V 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.
- 72. 72 Stock System Lower Charge Higher Charge Element Formula Name Formula Name Copper Cu+ copper (I) Cu2+ copper (II) Iron Fe2+ iron(II) Fe3+ iron(III) Lead Pb2+ lead (II) Pb4+ lead(IV) Mercury Hg2 2+ mercury(I) Hg2+ mercury(II) Tin Sn2+ Tin(II) Sn4+ Tin (II) Stock System Higher Charge Element Formula Name Formula Name Lower Charge
- 74. 74 ion charge ion name FeCl2 iron(II) chloride +2 -1 chloride iron(II) FeCl3 iron(III) chloride -1 +3 iron(III) chloride compound name
- 75. 75 ion charge ion name SnBr2 tin(II) bromide +2 -1 bromide tin(II) SnBr4 tin(IV) bromide -1 +4 tin(IV) bromide compound name
- 76. 76 The Classical System The Classical System
- 77. 77 In the Classical System the name of the metal (usually the Latin name) is modified with the suffixes -ous and ic.
- 78. 78 -ous lower charge -ic higher charge Metal name ends in nonmetal name ends in -ide
- 79. 79 Examples
- 80. 80 ion charge ion name FeCl2 ferrous chloride +2 -1 chloride ferrous FeCl3 ferric chloride -1 +3 ferric chloride compound name
- 81. 81 ion charge ion name SnBr2 stannous bromide +2 -1 bromide stannous SnBr4 stannic bromide -1 +4 stannic bromide compound name
- 82. 82 Lower Charge Higher Charge Element Formula Name Formula Name Copper Cu+ cuprous Cu2+ Cupric Iron Fe2+ ferrous Fe3+ ferric Lead Pb2+ plumbous Pb4+ plumbic Mercury Hg mercurous Hg2+ mercuric Tin Sn2+ stannous Sn4+ stannic Ion Names: Classical System
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