4.01. Ionic Compounds

Transcription

1 4.01. Ionic Compounds What happens when electrons interact? Dr. Fred Omega Garces Chemistry 111, Miramar College Ionic and Covalent Compounds

2 Regions of the Periodic Table Nonmetals, Metals, Metalloids, Noble gases Ionic and Covalent Compounds

3 Charge of Elemental Ions The common charge (oxidatio n state) of many represen tative and some transition metals elements can be determin e by the periodic table Ionic and Covalent Compounds

4 Classification of matter (compounds) Matter can be classified to mixtures and pure substances. Compounds falls under the category of pure substances Ionic and Covalent Compounds

5 Compounds and electron interactions Compounds can be broken up in a manner in which electrons from atoms interact with each other. If the electrons are mutually shared, these compounds are called Covalent Compounds. Pure Substances Compounds If the electrons are transferred, these compounds are called ionic compounds. Molecules Covalent Ionic Compounds Sharing electrons non-metals If the electrons are unequally shared, then these are called polar covalent compounds. Polar- Covalent unequal sharing electrons metals or non-metals transfer electrons metal + nonmetal Ionic and Covalent Compounds

6 Chemical Formulas Representation Representation of Molecules Chemical Name - Word name for chemical substance. i.e., water, methane, salt, acid, ammonia, glucose Chemical Formulas - General formula terminology for chemical substance i.e., NaCl, C 6 H 12 O 6, C 2 H 5 OH Molecular Formula-Formula for molecular substance which indicates type of atom and number of atoms. i.e, H 2 O, CH 4, NH 3, C 6 H 12 O 6 Structural Formula-Pictorial representation showing bonding connectivity of chemical substance; Empirical Formula-Lowest ratio of atoms in chemical substance; i.e., C 6 H 12 O 6 g CH 2 O Formula Unit-Empirical formula for ionic substances; NaCl, KOH, Fe(NO 3 ) Ionic and Covalent Compounds

7 Chemical Formulas Representation Representation of Molecules Chemical Name - Word name for chemical substance. i.e., water, methane, salt, acid, ammonia, glucose Chemical Formulas - General formula terminology for chemical substance i.e., NaCl, C 6 H 12 O 6, C 2 H 5 OH Molecular Formula-Formula for molecular substance which indicates type of atom and number of atoms. i.e, H 2 O, CH 4, NH 3, C 6 H 12 O 6 Structural Formula-Pictorial representation showing bonding connectivity of chemical substance; Empirical Formula-Lowest ratio of atoms in chemical substance; i.e., C 6 H 12 O 6 g CH 2 O Formula Unit-Empirical formula for ionic substances; NaCl, KOH, Fe(NO 3 ) Ionic and Covalent Compounds

8 How are compounds formed? Two main type of compounds Octet Rule: Atoms will transfer or share electrons in order to have the same number of electrons as its closest noble gas. Covalent compounds are formed by atoms sharing as many electrons needed to obey the Octet Rule Ionic and Covalent Compounds

9 Behavior of atoms to form Compounds Two main type of compounds Sodium and chlorine cooperate symbiotically in electron transfer in order to have eight electrons in its valence shell... Na. 11 p 12 n. F. 9 p 10 n F-. 9 p 10 n Na+. 11 p 12 n 11 p 12 n NaF. 9 p 10 n Fluorine prefers to share its electrons to obtain 8 total in its valence shell F 9 p 10 n. F 9 p 10 n 9 p 10 n F 2 9 p 10 n Atoms will transfer or share electrons in order to have the same number of electrons as its closest noble gas Ionic and Covalent Compounds

10 Forming Compounds from Elements Principle of electrical neutrality allows prediction of formulas of ionic compounds. Na Na + [Ne] 3s 1 e - [Ne] Cl Cl - [Ne] 3s 2 3p 5 [Ne]3S 2 3p 6 Force of attraction between ions lead to ionic bond formation. Na + + Cl - NaCl Ionic bond forms between Na + and Cl - due to electrostatic attraction between cation and anion. LATTICE ENERGY Ionic and Covalent Compounds

11 Three-Dimensional Lattice network NaCl - Crystalline solid in three-dimension. No such thing as a single NaCl entity. Instead a 3-D alternating lattice between Na + and Cl - is formed. Ionic compounds are all actually a lattice 3-D array arrangement. These atoms are held together by the lattice energy (electrostatic interaction.) The lattice energy of these ionic compound can be overcome by dissolving the solid in water Ionic and Covalent Compounds

12 Orbital Overlap and Electron Pairing H 1s + H 1s 1s H F 2p F 2p F 2p 1s 1s In the H 2 molecule the two overlapping 1s orbitals are occupied by the two 1s electrons with opposite spins. (The electrons, shown as arrows, spend most of its time between the nuclei but also moves throughout the overlapping orbital region) Ionic and Covalent Compounds H 2 H 1s F To maximize overlap in HF, half-filled 1s hydrogen orbital and Fluorine 2p orbital overlap along the long axis of the 2p orbital of fluorine. (The 2p x orbital is shown; the other two 2p orbitals of fluorine are not shown). 2p 2p F In F 2, the half-filled 2p x orbital of each fluorine faces end to end towards each other and overlap. The overlap of the orbitals creates the bond between the two fluorine atoms. F 2p

13 Oxidation numbers (common charge) Prediction of common charge of ion. From Periodic Table Atoms will lose or gain e - to have complete set of electrons in its outer most orbital. IA IIA IIIA IVA VA VIA VIIA VIIIA Exception Boron (will not form ion) Carbon Silicon ns 1 ns 2 ns 2 np 1 ns 2 np 2 ns 2 np 3 ns 2 np 4 ns 2 np 5 ns 2 np 6 Cation Cation Cation Anion Anion Anion Neutral Metals will lose electrons to form cations Non-metals will gain electrons to form anions Ionic and Covalent Compounds

14 Ion-charge atoms / group atoms Atoms Polyatomic Action /anions vs. Action /anions H + F - NH + 4 NO - 3 Li + Cl - Hg 2+ 2 SO 2-4 Na + Br - PO 3-4 K + I - CO 2-3 Mg +2 O 2 - Cr 2 O 2-7 Al +3 S 2 - OH Ionic and Covalent Compounds

15 Ion-charge atoms / group atoms Atoms Polyatomic Action /anions vs. Action /anions H + F - NH + 4 NO - 3 Li + Cl - Hg 2+ 2 SO 2-4 Na + Br - PO 3-4 K + I - CO 2-3 Mg +2 O 2 - Cr 2 O 2-7 Al +3 S 2 - OH Ionic and Covalent Compounds

16 Ionic Compound: KF Metals (or cation) involved Chemical formula - Principle of electrical neutrality is applied in order to predict formulas of ionic compound. Example 1: Potassium and Fluorine K K + F F - KF Potassium and fluorine combine in a 1:1 ratio because potassium (K) is positive one (+1) and fluorine (F) is negative one (-1). Only in a 1:1 combination will the charges cancel each other Ionic and Covalent Compounds

17 Principle of Electrical Neutrality When elements combine to form compounds, the principle of electrical neutrality allows prediction of formulas of the ionic compound. Basic idea: Sum of the charges must add to zero. That is the sum of the cation charge and the sum of the anion charge must cancel each other so that the compound form is neutral. M m+ + X n- g M n X m S cation (charges) = S anion (charges) Ionic and Covalent Compounds

18 Criss-Cross method 1. Write the symbols for the cation and the anion. 2. Use a superscript for the charge (+/-) of each ion. 3. Criss-cross step: Criss-cross the superscript of the cation to the subscript position of the anion (disregard the positive sign). Criss-cross the superscript of the anion to the subscript position of the cation (disregard the negative sign). 4. Remove the superscript from both cation and anion. 5. If possible, divide the subscripts by their greatest common factor to reduce to simplest whole ratio. Example 1: Barium and nitrogen Ba Ba 2+ N N 3- Ba 2+ N 3- Ba 3 N 2 Barium and nitrogen combine in a 3 : 2 ratio because barium (B) is positive three (+2) and nitrogen (N) is negative three (-3). Only in a 3:2 combination will the charges cancel each other Ionic and Covalent Compounds

19 Ionic Compound: Al 2 S 3 Writing the formula for an ionic compound involves writing the cation and anion ration so that there is a net zero charge or the compound is electrical neutrality. That is sum of the charges of all ions in the compound equals zero. Example 2: Aluminum and Sulfur Al Al +3 S S -2 Al +3 S -2 Al 2 S 3 Aluminum and sulfur combine in a 2 : 3 ratio because aluminum (Al) is positive three (+3) and sulfur (S) is negative two (-2). Only in a 2:3 combination will the charges cancel each other Ionic and Covalent Compounds

20 Predicting Formulas of Ionic Compounds Cation + Anion Electrostatic attraction g electrically neutrality Represent ionic compound by empirical formula Na + I 2 -in waterg Na I - Na + + Na + + I- + I- g NaI + NaI G-IA G-VIIA -in waterg NaI Sodium Iodide Similarly, Na + O 2 g 4 Na + + 2O -2 g Na 2 O Co + SO 4 2- g 2 Co SO 4 2- g Co 2 (SO 4 ) 3 Sodium oxide Cobalt(III) sulfate Side notes: Diatomic molecules: H 2, N 2, O 2, F 2, Cl 2, Br 2, I Ionic and Covalent Compounds

21 Chemical Formula Summary Compounds can be formed by elements combining and i) electron transfer occurs, here ionic compounds forms. ii) electrons are shared between elements if there is mutually sharing, covalent compounds forms if there is unequal sharing, polar covalent compounds forms Compounds are always electrically neutral For ionic compounds, Principle of Electrical Neutrality is obeyed. For covalent compounds, There is no charge with the elements in the compound electrons are shared. Electrical Neutrality does not apply. Ionic substances will dissociate in water into their ions Covalent compounds stays intact in water as their molecules Ionic and Covalent Compounds

22 4.01b. Ionic Compounds What happens when electrons interact? Dr. Fred Omega Garces Chemistry 111, Miramar College Ionic and Covalent Compounds

23 Charge of Elemental Ions; Revisited The common charge (oxidatio n state) of many represen tative and some transition metals elements can be determin e by the periodic table Ionic and Covalent Compounds

24 Example of polyatomic ions Most common polyatomic ions Polyatomic anions Previously we discussed how ions are formed from elements. Ions can also be formed from group of atoms that are covalently held together. These group of atoms which are charged are called polyatomic ions. Top thirteen of this ions are summarized here. 12. Chromate 11. Permanganate 10. Perchlorate 9. Dichromate 8. Acetate 7. Carbonate 6. Phosphate 5. Sulfate 4. Nitrate CrO 2-4 MnO - 4 ClO - 4 Cr 2 O 2-7 CH 3 CO - 2 CO 2-3 PO 3-4 SO 2-4 NO - 3 Cations 3. Cyanide CN - Ammonium NH Peroxide O Hydroxide OH Ionic and Covalent Compounds

25 Extensive List of Polyatomic ions Ionic and Covalent Compounds

26 Common polyatomic ions Cations : ammonium NH + 4 & Hg 2+ 2 Anions (charge)- -1: hydroxide, OH - ; cyanide, CN - ; nitrate, NO - 3-2: carbonate, CO 2-3, chromate CrO 2-4, Dichromate Cr 2 O 2-7, sulfate SO : phosphate, PO 3-4 Polyatomic oxy-ions: Chlorate, bromate, iodinate, sulfate, nitrate, phosphate, chromate Some form four anions chlorate: perchlorate g chlorate g chlorite g hypochlorite Some form only two oxy anions sulfate: sulfate sulfite Some form only on oxy anion carbonate: carbonate Ionic and Covalent Compounds

27 ... helpful hints about anions -ide -ate -ite elemental ions oxy ions oxy ions X -m XO -m n XO -m n-1 P -3 phosphide PO -3 phosphate 4 PO -3 phosphite 3 As -3 arsenide AsO -3 arsenate 4 AsO -3 arsenite 3 S -2 sulfide SO -2 sulfate 4 SO -2 sulfite 3 Se -2 selenide SeO -2 selenate 4 SeO -2 selenite 3 N -3 nitride NO - 3 nitrate NO - 2 nitrite Cl - chloride ClO - 3 chlorate ClO - 2 chlorite Br - bromide BrO - 3 bromate BrO - bromite 2 I - iodide IO - 3 iodate IO - 2 iodite Ionic and Covalent Compounds

28 Chemical Nomenclature: Ways Compounds Ionic and Covalent Forms Ionic Compounds: Type I & II Binary Form - Composed from two different elements bonding. Polyatomic Form - Compounds with some part of substituents clustered together covalently with some charge. Covalent Compounds: Type III Combination of nonmetal atoms sharing electrons Ionic and Covalent Compounds

29 Type I, II and III Ionic : Type I & II Type I : Metal - nonmetal metal has a definite oxidation state. Ca g Ca +2, K g K +, Al g Al +3, Zn g Zn +2 Type II : Metal(Ox#) - nonmetal metal has a variable oxidation state. Cu g Cu +2 or Cu +, Cr g Cr +2 or Cr +4 Molecular: Type III Type III : (prefix 1 )nonmetal 1 - (prefix 2 )nonmetal 2 Elements have no charge covalent type of compounds Ionic and Covalent Compounds

30 Determining Type (I, II, III) of Compound Show me the metal!! Type I or Type II N o Yes Is the metal Group I, II or Al, Zn, Cd, Ag, and N o Yes NH 4 + Type I metal-nonmetal Type II metal(ox.#)-nonmetal Type III (Prefix)nonmetal 1 (Prefix)nonmetal Ionic and Covalent Compounds

31 I II Type I, II and III Type Anion elemental Anion polyatomic (Metal nonmetal) Cation; Rep Metal Cation - Anion (Metal - nonmetal) (Transition) metal Cation (O St #) - Anion Cation ; 3rd row and lower Cation - Anion(ide) Al 2 O 3 ; Aluminum oxide Ag 2 S; Silver sulfide Cation (oxidation st.) Anion(ide) FeCl 3 ; Iron(III) chloride PbS 2 ; Lead(IV) sulfide Cation - Anion Cd(NO 3 ) 2 : cadmium nitrate (NH 4 ) 2 SO 4 : ammonium sulfate Cation (oxidation st.) Anion Sn(C 2 H 3 O 2 ) 2 ; Tin(II) acetate Au 3 PO 3 ; Gold(I) phosphite Old method (Fe +3 vs Fe +2 ) higher ox.st. -ic lower ox. st. -ous III Molecular compounds - Compounds contains nonmetal (Prefix) nonmetal 1 - (Prefix ) nonmetal 2 Cation(ic) - Anion(ide) FeBr 3 ; Ferrric bromide Iron(III) bromide Cation(ous) Anion(ide) Fe 3 N 2 ; Ferrrous nitride Iron(II) nitride (Prefix) nonmetal 1 - Cation(ic) Polyatomic anion Fe(NO 3 ) 3 ; Ferrtic nitrate Iron(III) nitrate Cation(ous) Polyatomic anion Fe(NO 2 ) 2 ; Ferrrous nitrite Iron(II) nitrite (Prefix) nonmetal 2 (ide) Prefixes are indication of the number of atoms: mono-, di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona-, deca- order of naming nonmetal 1 & nonmetal (ide) 2 nonmetal 1 is to the left and bottom of nonmetal 2 based on it is named first in the nomenclature scheme. Si - C - As - P - N - H - Se - S - I - Br - Cl - O - F S & 3 O forms SO 3 ; Sulfur trioxide 2 P & 5 O forms P 2 O 5 ; Diphosphorus pentoxide Ionic and Covalent Compounds

32 I II Type I, II and III Type Anion elemental Anion polyatomic (Metal nonmetal) Cation; Rep Metal Cation - Anion (Metal - nonmetal) (Transition) metal Cation (O St #) - Anion Cation ; 3rd row and lower Cation - Anion(ide) Al 2 O 3 ; Aluminum oxide Ag 2 S; Silver sulfide Cation (oxidation st.) Anion(ide) FeCl 3 ; Iron(III) chloride PbS 2 ; Lead(IV) sulfide Cation - Anion Cd(NO 3 ) 2 : cadmium nitrate (NH 4 ) 2 SO 4 : ammonium sulfate Cation (oxidation st.) Anion Sn(C 2 H 3 O 2 ) 2 ; Tin(II) acetate Au 3 PO 3 ; Gold(I) phosphite Old method (Fe +3 vs Fe +2 ) higher ox.st. -ic lower ox. st. -ous III Molecular compounds - Compounds contains nonmetal (Prefix) nonmetal 1 - (Prefix ) nonmetal 2 Cation(ic) - Anion(ide) FeBr 3 ; Ferrric bromide Iron(III) bromide Cation(ous) Anion(ide) Fe 3 N 2 ; Ferrrous nitride Iron(II) nitride (Prefix) nonmetal 1 - Cation(ic) Polyatomic anion Fe(NO 3 ) 3 ; Ferrtic nitrate Iron(III) nitrate Cation(ous) Polyatomic anion Fe(NO 2 ) 2 ; Ferrrous nitrite Iron(II) nitrite (Prefix) nonmetal 2 (ide) Prefixes are indication of the number of atoms: mono-, di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona-, deca- order of naming nonmetal 1 & nonmetal (ide) 2 nonmetal 1 is to the left and bottom of nonmetal 2 based on it is named first in the nomenclature scheme. Si - C - As - P - N - H - Se - S - I - Br - Cl - O - F S & 3 O forms SO 3 ; Sulfur trioxide 2 P & 5 O forms P 2 O 5 ; Diphosphorus pentoxide Ionic and Covalent Compounds

33 Distinguishing between elemental & polyatomic ions Identify: - Type-I - Type-II - Type-III - - Acids Which Type-I and Type-II contains polyatomic ions? 1 1 Mg(ClO 3 ) CuBr 2 A2 HClO 115 KMnO 4 33 N 2 O Na 2 O NH 4 NO XeF Na 3 As 218 HgCO 3 A6 HI A19 H 2 SO NaHCO NH 4 ClO Zn(C 2 H 3 O 2 ) Li 2 Se 29 V 3 N 1 22 CdCO PbTe H 2 O NaHSO (NH 4 ) 2 S A12 HC 2 H 3 O FrF 313 SO NiO Ionic and Covalent Compounds A aluminum sulfate B Palladium (II) chromate C tungsten(iv) hypochlorite D ammonium bisulfate E Tetraphosphorus octaoxide F cobalt(iii) phosphide G calcium phosphate H cesium acetate I xenon dioxide J silver permanganate K platinum (IV) periodate L magnesium phosphite M chlorine monobromide N Mercury(I) telluride O Cadmium biphosphate

34 Distinguishing between elemental & polyatomic ions Identify: 1- Type-I 2- Type-II 3- Type-III - A- Acids Which Type-I and Type-II contains polyatomic ions? 1 Mg(ClO 3 ) 2 2 CuBr 2 A HClO 1 KMnO 4 3 N 2 O 4 1 Na 2 O 2 1 NH 4 NO 2 3 XeF 4 1 Na 3 As 2 HgCO 3 A HI A H 2 SO 4 1 NaHCO 3 1 NH 4 ClO 4 1 Zn(C 2 H 3 O 2 ) 2 1 Li 2 Se 2 V 3 N 1 CdCO 3 2 PbTe 2 3 H 2 O 2 1 NaHSO 3 1 (NH 4 ) 2 S A HC 2 H 3 O 2 1 FrF 3 SO 3 2 NiO 2 1 aluminum sulfate 2 palladium (II) chromate 2 tungsten(iv) hypochlorite 1 ammonium bisulfate 3 tetraphosphorus octaoxide 2 cobalt(iii) phosphide 1 calcium phosphate 1 cesium acetate 3 xenon dioxide 1 silver permanganate 2 platinum (IV) periodate 2 manganese(iv) phosphite 3 chlorine monobromide 2 mercury(i) telluride 1 cadmium biphosphate Type Ionic I, and 5 type Covalent II, Compounds 4 type III 4 Acids = 26 6 Type I, 5 type II, 4 type III

35 Example: Type-I Given the Chem Formula provide the name Name Type I: Binary Metal - nonmetal(ide) SrSe Mg 3 N 2 Li 2 O Strontium selenide Magnesium nitride Lithium oxide Chem Formula Type I: SrSO 4 Mg 3 (PO 4 ) 2 LiClO 4 Polyatomic Metal - polyatomic Strontium sulfate Magnesium phosphate Lithium perchlorate Ionic and Covalent Compounds

36 Example: Type-I Given the Chem Formula provide the name Name Type I: Binary Metal - nonmetal(ide) SrSe Strontium selenide Mg 3 N 2 Li 2 O Chem Formula Type I: SrSO 4 Mg 3 (PO 4 ) 2 LiClO 4 Magnesium nitride Lithium oxide Polyatomic Metal - polyatomic Strontium sulfate Magnesium phosphate Lithium perchlorate Ionic and Covalent Compounds

37 Example: Type-I Given the name provide the chemical formula Name Type I: Binary Metal - nonmetal(ide) potassium sulfide Elemental symbol K & S Charge of ions K (+1) S(-2) Criss-Cross K(2) S(1) g K 2 S Chem Formula Type I: Cadmium bisulfite Polyatomic Metal - polyatomic Elemental symbol Cd & HSO 3 Charge of ions Cd (+2) HSO 3 (-1) Criss-Cross Cd(1) HSO 3 (2) g Cd(HSO 3 ) Ionic and Covalent Compounds

38 Example: Type-I Given the name provide the chemical formula Name Type I: Binary Metal - nonmetal(ide) potassium sulfide Elemental symbol K & S Charge of ions K (+1) S(-2) Criss-Cross K(2) S(1) g K 2 S Chem Formula Type I: Cadmium bisulfite Polyatomic Metal - polyatomic Elemental symbol Cd & HSO 3 Charge of ions Cd (+2) HSO 3 (-1) Criss-Cross Cd(1) HSO 3 (2) g Cd(HSO 3 ) Ionic and Covalent Compounds

39 Example: Type-II Given the Chem Formula provide the name Name Type II: Binary Metal(Ox.#) - nonmetal(ide) Mn 3 N 2 Elemental symbol Mn (3) & N (2) Chem Formula Type II: Reverse Criss-Cross Mn (2) & N (3) Ox. State of metal Ox St = 2; Mn(II) Name of Chemical Manganese(II) nitride Polyatomic Metal(Ox#) - polyatomic Mn(NO 2 ) 2 Elemental symbol Mn (1) & NO 2 (2) Reverse Criss-Cross Mn (2) & NO 2 (1) Ox. State of metal Ox St= 2; Mn(II) Name of Chemical Manganese(II) nitrite Ionic and Covalent Compounds

40 Example: Type-II Given the Chem Formula provide the name Name Type II: Binary Metal(Ox.#) - nonmetal(ide) Mn 3 N 2 Elemental symbol Mn (3) & N (2) Reverse Criss-Cross Mn (2) & N (3) Ox. State of metal Ox St = 2; Mn(II) Name of Chemical Manganese(II) nitride Chem Formula Type II: Polyatomic Metal(Ox#) - polyatomic Mn(NO 2 ) 2 Elemental symbol Mn (1) & NO 2 (2) Reverse Criss-Cross Mn (2) & NO 2 (1) Ox. State of metal Ox St= 2; Mn(II) Name of Chemical Manganese(II) nitrite Ionic and Covalent Compounds

41 Example: Type-II Given the name provide the chemical formula Name Type II: Binary Metal - nonmetal(ide) Iron(II) sulfide Elemental symbol Fe & S Charge of ions Fe(+2) S(-2) Criss-Cross Fe(2) S(2) g Fe 2 S 2 Reduce ratio FeS Name Type II: Polyatomic Metal - polyatomic Tin(IV) sulfite Elemental symbol Sn & SO 3 Charge of ions Sn(+4) SO 3 (-2) Criss-Cross Sn(2) SO 3 (4) g Sn 2 (SO 3 ) 4 Reduce ratio Sn(SO 3 ) Ionic and Covalent Compounds

42 Example: Type-II Given the name provide the chemical formula Name Type II: Binary Metal - nonmetal(ide) Iron(II) sulfide Elemental symbol Fe & S Charge of ions Fe(+2) S(-2) Criss-Cross Fe(2) S(2) g Fe 2 S 2 Reduce ratio FeS Name Type II: Polyatomic Metal - polyatomic Tin(IV) sulfite Elemental symbol Sn & SO 3 Charge of ions Sn(+4) SO 3 (-2) Criss-Cross Sn(2) SO 3 (4) g Sn 2 (SO 3 ) 4 Reduce ratio Sn(SO 3 ) Ionic and Covalent Compounds

43 Example: Type-III Given the Chem Formula determine the name Name Type III: (prefix 1 )nonmetal 1 - (prefix 2 )nonmetal 2 (ide) N 2 O 2 Elemental symbol N (2) & O (2) Prefix dinitrogen & dioxide Name of Chemical dinitrogen dioxide XeF 2 Elemental symbol Xe (1) & F(2) Prefix monoxenon & difluoride Name of Chemical xenon difluoride P 4 Se 10 Elemental symbol P (4) & Se(10) Prefix tetraphosphorus & decaselenide Name of Chemical tetraphosphorus decaselenide Ionic and Covalent Compounds

44 Example: Type-III Given the Chem Formula determine the name Name Type III: (prefix 1 )nonmetal 1 - (prefix 2 )nonmetal 2 (ide) N 2 O 2 Elemental symbol N (2) & O (2) Prefix dinitrogen & dioxide Name of Chemical dinitrogen dioxide XeF 2 Elemental symbol Xe (1) & F(2) Prefix monoxenon & difluoride Name of Chemical xenon difluoride P 4 Se 10 Elemental symbol P (4) & Se(10) Prefix tetraphosphorus & decaselenide Name of Chemical tetraphosphorus decaselenide Ionic and Covalent Compounds

45 Example: Type-III Given the name determine the chemical formula Name Type III: (prefix 1 )nonmetal 1 - (prefix 2 )nonmetal 2 (ide) Diboron trisulfide Elemental symbol B & S Prefix for atoms B(2) & S(3) Chemical formula B 2 S 3 Silicon tricarbide Elemental symbol Si & C Prefix for atoms Si(1) & C(3) Chemical formula SiC 3 Iodine monochloride Elemental symbol I & Cl Prefix for atoms I(1) & Cl(1) Chemical formula ICl Ionic and Covalent Compounds

46 Example: Type-III Given the name determine the chemical formula Name Type III: (prefix 1 )nonmetal 1 - (prefix 2 )nonmetal 2 (ide) Diboron trisulfide Elemental symbol B & S Prefix for atoms B(2) & S(3) Chemical formula B 2 S 3 Silicon tricarbide Elemental symbol Si & C Prefix for atoms Si(1) & C(3) Chemical formula SiC 3 Iodine monochloride Elemental symbol I & Cl Prefix for atoms I(1) & Cl(1) Chemical formula ICl Ionic and Covalent Compounds

47 Summary An ionic compound is named with cation first and anion last. For metals that can form more than one ion, the charge is shown with a Roman numerical. For example, copper forms the mono-cation Cu + and the di-cation, Cu 2+, these are distinguished from each other in their chemical name as copper(i) and copper (II). Oxyanions (or anions with two kinds of element one of which is oxygen) have suffixes, and some have prefixes attached to their element root name to indicate the number of oxygen atoms. For example the oxy anion containing sulfur & oxygen may form the following anions, hyposulfite SO 2-2, sulfite SO 2-3, sulfate SO 2-4, and persulfate SO 2-5. Binary covalent compounds nomenclature consist of writing the most electropositive elements first proceeded by a prefix which indicates the number of atoms, I.e., di-2, tri-3, tetra-4 and so on. The second more electronegative element is written next which also is proceeded by the prefix which indicates the number of atoms. For the second element, a mono prefix must always be written if there is only one atom in the chemical formula. i.e., carbon monoxide for CO Ionic and Covalent Compounds