Naming inorganiccompoundsMUDr. Jan Pláteník, PhDAtom Smallest particle of a pure element having itschemical properties Positively charged nucleus (protons, neutrons) Negatively charged electron shell:– Electron is wave/particle– Behavior of electron described by quantum mechanics(. wave function, quantum numbers)– Orbital: space area within the atom shell whereoccurrence of an electron or pair of electrons is moreprobable Structure of electron shell determines chemicalproperties– Valence electrons– The octet rule1

Periodic table of elements"Periodic table (polyatomic)" by DePiep - Own work. Licensed under Creative Commons Attribution-ShareAlike 3.0 via Wikimedia Commons table (polyatomic).svg#mediaviewer/File:Periodic table(polyatomic).svgMolecular (covalent) compounds Consist of particles (molecules) made of severalatoms connected with covalent bonds Examples of molecules:H H– Gases: diatomic– H2O, NH3 etc.HOHH N HH– Covalently-bonded crystals: diamond– Macromolecules of proteins and nucleic acids2

Diamond and graphiteFig. from WikipediaCovalent chemical bond Most often between two non-metals Chemical bond that results from two nuclei attractingthe same pair(s) of electrons Based on electron sharingHHHH If more pairs shared double or triple bonds Some atoms may also have nonbonding (lone) electronpairs3

Valence Number of covalent bonds formed by anatom The octet rule: tendency to achieve electronconfiguration of the nearest noble gas– e.g. H-F: H achieves configuration of He,F configuration of Ne Therefore O usually bivalent, N trivalent,C tetravalent etc.Coordination covalent bond (also dative, donor-acceptor bond) Both bonding electrons provided by one ofthe atoms (donor), whereas the other atomsprovides an empty orbital (akceptor)4

Ionic compounds Consist of chargedparticles (ions) heldtogether by ionic bonds Metal non-metal(s) Cations ( ) and anions (-)combine in space toachieve electroneutralityIons Charged because number of electrons doesnot match number of protons Tendency to form ions depends onelectronegativity of element Monoatomic: Na , Cl-, H , Fe2 Polyatomic: NO3- , SO42 Complex: [Fe(CN)6]4-5

Polyatomic ions of oxo-acids:e.g. sulfate, SO42- :resonance stabilization of sulfate ion.similar is nitrate NO3-, phosphate PO43-, carbonate CO32-, etc.Coordination (complex) ionse.g. [Fe(CN)6]4- central atom oftransition metalproviding emptyorbitals ligands providing freeelectron pairs Number of ligands(coordination number)is usually 4 or 66

Ionic salts: no true molecule Crystal lattice of NaCl:Formula unit Dissolution of NaCl in water: electrolytic dissociationproducing hydrated independent ions Na , Cl-Chemical formulas Stoichiometric (empirical):– e.g.: glucose CH2O; sodium chloride NaCl Molecular:– e.g.: glucose C6H12O6; sodium chloride NaCl Structural:7

Polarity of chemical bondDetermined by difference in electronegativityof the two connected atoms: 0.4 nonpolar covalent bondGraduale.g. H-H, carbon-hydrogentransition !0.4 - 1.7 polar covalent bonde.g. H-O-H, NH3, carbon-oxygen, carbon-nitrogen 1.7 ionic bonde.g NaCl.Oxidation number (formal valency) Oxidation number of element in compoundequals its charge after giving all bondingelectron pairs to the more electronegativeatom Can be zero, positive or negative integer Basis for nomenclature of inorganiccompounds Redox reactions: oxidation numberincreases in oxidation, decreases inreduction8

Rules for determination of oxidationnumbers Free electroneutral atom, or atom in molecule of pureelement: oxidation number 0 Oxidation number of a monoatomic ion equals itscharge In heteroatomic compounds the bonding electrons aregiven to the more electronegative atom, practically:– H has nearly always oxidation number I (only inmetallic hydrides -I)– O almost always -II (only in peroxides -I)– F always -I– Alkali metals (Na, K.) always I– Alkaline earth elements (Ca, Mg.) always IIRules for determination of oxidationnumbersExamples:CO2 : CIV, O-IIH2SO4: HI, SVI, O-IISum of oxidation numbers of all atoms in electroneutralmolecule is 0, in polyatomic ion equals the ion chargee.g: CO32-: CIV,O-II1 IV 3 (-II) -29

Czech nomenclature of oxides:Oxidation tý-ečný/-ičný-ový-istýGeneral formulaX2OXOX2O3XO2X2O5XO3X2O7-ičelýXO4Naming Binary Ionic Compounds Compounds of one metallic element and onenonmetal (e.g. metallic oxides, hydroxides,halogenides, sulfides) Name of metal stem of nonmetal -ide Examples:– Al2O3, aluminum oxide– Ba(OH)2, barium hydroxide– KCl, potassium chloride– ZnS, zinc sulfide10

Naming Binary Ionic Compounds Numerical prefixes are never used. If the metal can exist in more oxidation states,its oxidation number is included to the name Examples:– FeCl3, iron(III) chloride (ferric chloride)– FeCl2, iron(II) chloride (ferrous chloride)– CuO, copper(II) oxide (cupric oxide)– Cu2O, copper(I) oxide (cuprous oxide)Naming Binary Molecular Compounds Compounds of two nonmetals (e.g. oxides ofnonmetals) Name of less electronegative element stem ofthe other element -ide Numerical prefixes precede names of bothnonmetals Examples:– CO, carbon monoxide– N2O5, dinitrogen pentoxide– CCl4, carbon tetrachloride– H2S, hydrogen sulfide11

Numerical ahepta-8octa-8nona-10deca-Naming acids and their saltsBrønsted-Lowry concept of acids and bases: Acid is a proton donor Base is a proton acceptorHCl(aq) H2O(l)AcidBaseH3O (aq) Cl-(aq)ConjugateacidConjugatebaseSalt: ionic compound, product of neutralizationreaction between acid and base (the acidicproton replaced with metal cation)12

Naming acids and their saltsA) hydroacids:Gaseous nonmetallic hydrides whose aqueoussolutions are acidicE.g. HCl, hydrochloric acid (aqueoushydrogen chloride), salts: chlorideLikewise:– HBr, hydrobromic acid, salts bromides– H2S, hydrosulfuric acid, salts sulfides– HCN, hydrocyanic acid, salts cyanidesNaming acids and their saltsB) oxo-acids:Central atom -OH groups, protonsdissociate from oxygen. In salts appear aspolyatomic anionsIf only one oxidation state of the central atomis possible:Stem of the central atom -ic acidE.g. H2CO3, carbonic acid, salt: carbonate13

Naming acids and their saltsB) oxo-acids:If there are two possible oxidation states ofthe central atom:Higher ox. number: -ic acid, salt: -ateLower ox. number: -ous acid, salt: -iteExample:H2SO4, sulfuric acid, salt: sulfateH2SO3, sulfurous acid, salt: sulfiteNaming acids and their saltsB) oxo-acids:If there are more than two possible oxidationstates of the central atom, prefixes are used:HClO, hypochlorous acid, salt: hypochloriteHClO2, chlorous acid, salt: chloriteHClO3, chloric acid, salt: chlorateHClO4, perchloric acid, salt: perchlorate14

The oxidation numbers can also beused with metals in anions:MnO42-: manganate(VI) or just manganateMnO4-: manganate(VII) or permanganate[Fe(CN)6]4-: hexacyanoferrate(II)or ferrocyanide[Fe(CN)6]3-: hexacyanoferrate(III)or ferricyanideNaming coordination compounds Names of neutral bonyl Names of anionic ligands always end in –o:–––––––F Cl Br I OH CN etc.fluorochlorobromoiodohydroxocyano15

Naming coordination compounds1. Complex particle is cation:e.g. [Cu(NH3)4]SO4[Cu(NH3)4]2 SO42 Tetraamminecopper(II) sulfate2. Complex particle is anion:e.g. K3[CoF6]3 K [CoF6]3 Potassium hexafluorocobaltate(III)Naming coordination compounds3. Both cation and anion are complexes:e.g. [Pt(NH3)4][PtCl4][Pt(NH3)4]2 [PtCl4]2 Tetraammineplatinum(II) tetrachloroplatinate(II)4. Neutral complexes:e.g. [CrCl3(H2O)3]Triaquatrichlorochromium(III) complex16