1. 4 - 1 CH110: Chapter 4 CH110 Chapter 6: Ionic & Molecular Compounds Ions Ionic Compounds Covalent Compounds Molecular Shapes & Polarity Attractive Forces

2. 4 - 2 CH110: Chapter 4 Electron arrangement 2 8 18 32 Electrons fill layers around nucleus Low  High Electrons fill layers around nucleus Low  High Shells = Energy levels 2412 Mg A new layer is added for each row or period in the table. A new layer is added for each row or period in the table.

3. 4 - 3 CH110: Chapter 411H 73Li 42He IA IIA 94Be 2, 1 2, 2

4. 4 - 4 CH110: Chapter 4115B 11H 73Li IA IIA IIIA 94Be 2, 1 2, 2 2, 3

5. 4 - 5 CH110: Chapter 4115B 126C 137N IIIA IVA VA 2, 3 2, 4 2, 5

6. 4 - 6 CH110: Chapter 494Be 11H 73Li 42He 2010Ne 2311 Na 2412 Mg 4018 Ar IA IIA VIIIA 2, 1 2, 2 2, 8, 1 2, 8, 2 2, 8 2, 8, 8

7. 4 - 7 CH110: Chapter 4 33 2412 Mg 11H 73Li 2311 Na 94Be 115B 2713 Al Valence electrons Where most chemical Reactions occur.1122 2, 1 2, 2 2, 8, 1 2, 8, 2 2, 3 2, 8, 3

8. 4 - 8 CH110: Chapter 411H 73Li 42He 94Be 2010Ne 2311 Na 2412 Mg 4018 Ar 881122 2, 1 2, 2 2, 8 2, 8, 1 2, 8, 2 2, 8, 8 Octet Rule

9. 4 - 9 CH110: Chapter 411H 73Li 2311 Na Lewis Structures Show only Valence Electrons H Li Na K

10. 4 - 10 CH110: Chapter 4 H Li Na K He Be B C O F Ne N Mg Ca Al Ga Si Ge P As S Se ClBrArKr 1 234567 8

11. 4 - 11 CH110: Chapter 4 2311 Na Ions Metals give e - s to make Cations Na 11 +’s 11 -’s 0 11 +’s 11 -’s 0 11 +’s 10 -’s 1 + 1 + 11 +’s 10 -’s 1 + 1 + Na 1+ 2, 8 = [Ne] 2, 8, 1

12. 4 - 12 CH110: Chapter 4 Ions Nonmetals take e - s to make Anions 17 +’s 17 -’s 0 17 +’s 17 -’s 0 17 +’s 18 -’s 1 - 1 - 17 +’s 18 -’s 1 - 1 - Cl 1- 3517 Cl = Cl 1- 2, 8, 8 = [Ar] 2, 8, 7

13. 4 - 13 CH110: Chapter 4 Formation of NaCl Na + Cl Na + + Cl + and - ions attract to form an ionic bond. _ e- moves from Metal  Nonmetal Metal Cation Nonmetal Anion Stable octets

14. 4 - 14 CH110: Chapter 4 Ionic compounds Not individual molecules Form crystal arrays Ions touch many others Formula represents the average ion ratio NaCl sodium chloride NaCl sodium chloride Na Cl

15. 4 - 15 CH110: Chapter 4 Common ions 4 - 6 1+ 2+2+3+3+ 4+4-4+4- 3-3-2-2-1-1- Representative Elements

16. 4 - 16 CH110: Chapter 4 Ionic Formulas Metal Cations + Nonmetal Anions Na 1+ Cl 1- NaCl Sodium Chloride Al 3+ Cl 1- AlCl 3 Aluminum Chloride Cl 1-

17. 4 - 17 CH110: Chapter 4 Common ions H Li Na Cs Rb K TlBa Fr He RnAtPoBiPb Be Mg Sr Ca Ra InXeITeSbSn GaKrBrSeAsGe AlArClSPSi BNeFONC HgAuHfLsPtIrOsReWTa CdAgZrYPdRhRuTcMoNb Ac ZnCuTiScNiCoFeMnCrV Gd Cm Tb Bk Sm Pu Eu Am Nd U Pm Np Ce Th Pr Pa Yb No Lu Lr Er Fm Tm Md Dy Cf Ho Es 1+ 2+2+3+3+ 4+4-4+4- 3-3-2-2-1-1- Transition Elements VariableVariable Representative Elements

18. 4 - 18 CH110: Chapter 4 Information in the table Fe 55.845 Elemental Symbol Electronic Configuration Atomic mass (weight) 26 Iron 2,3 [Ar]3d 6 4s 2 Atomic number Name of the element Oxidation states (Valence) (Valence) Oxidation states (Valence) (Valence)

19. 4 - 19 CH110: Chapter 4 Transition Metal Ions Fe 2+ Cl 1- FeCl 2 Iron (II) Chloride Fe 3+ Cl 1- FeCl 3 Iron (III) Chloride Cl 1- Ferrous Chloride Ferric Chloride

20. 4 - 20 CH110: Chapter 4 Polyatomic Ions Na 1+ SO 4 2- Na 2 SO 4 Sodium Sulfate NH 4 1+ PO 4 3- (NH 4 ) 3 PO 4 Ammonium Phosphate NH 4 1+ Na 1+

21. 4 - 21 CH110: Chapter 4 Ionic compounds Na + Mg 2+ Al 3+ Cl - O 2- N 3- Some simple ions NaCl Anions Cations Na 2 O Na 3 N MgCl 2 AlCl 3 MgO Al 2 O 3 Mg 3 N 2 AlN

22. 4 - 22 CH110: Chapter 4 Ionic compounds Cations Anions Na 1+ Mg 2+ Al 3+ Br 1- O 2- N 3- NaBr Na 2 O Na 3 N MgBr 2 AlBr 3 MgO Al 2 O 3 Mg 3 N 2 AlN Fe 3+ Cu 1+ FeBr 3 Fe 2 O 3 FeN CuBr Cu 2 O Cu 3 N Sodium Bromide Sodium Oxide Sodium Nitride Magnesium Bromide Aluminum Bromide Iron (III) Bromide Ferric Bromide Copper (I) Bromide Cuprous Bromide Magnesium Oxide Aluminum Oxide Iron (III) Oxide Ferric Oxide Copper (I) Oxide Cuprous Oxide Magnesium Nitride Aluminum Nitride Iron (III) Nitride Ferric Nitride Copper (I) Nitride Cuprous Nitride

23. 4 - 23 CH110: Chapter 4 H Li Na K He Be B C O F Ne N Mg Ca Al Ga Si Ge P As S Se ClBrArKr 1 234567 8 Metals give e-s to nonmetals Nonmetals Share e-s with other nonmetals

24. 4 - 24 CH110: Chapter 4 Covalent Bonds HH + HHClO + O + + N N N NO O

25. 4 - 25 CH110: Chapter 4 Covalent Bonds HH Cl N NO O H 2 H-H H 2 Cl 2 Cl-Cl Cl 2 O 2 O=O O 2 N N2N2N2N2

26. 4 - 26 CH110: Chapter 4 Covalent compounds Discrete molecular units Atoms held together by bonds Covalent compounds exist in all states (CO 2 - gas, H 2 O - liquid, SiO 2 - solid) Formula represents atoms in a molecule Covalent compounds O=O

27. 4 - 27 CH110: Chapter 4 OC OC Covalent Bonds O=C=O C O O CO Carbon monoxide Carbon dioxide CO 2 May modify rules to improve the sound. Example Example - use monoxide not monooxide.

28. 4 - 28 CH110: Chapter 4 CO CO 2 N2O5N2O5 SiO 2 ICl 3 P2O5P2O5 CCl 4 Naming covalent compounds May modify rules to improve the sound. Example Example - use monoxide not monooxide. carbon tetrachloride diphophorous pentoxide iodine trichloride silicon dioxide carbon monoxide carbon dioxide dinitrogen pentoxide

29. 4 - 29 CH110: Chapter 4 Bond Polarity, Electronegativity Cl H Electrons in covalent bonds rarely get shared equally. H Cl

30. Electronegativity Relative ability of atoms to attract e -. At I Br Cl Po Te Se S Bi Sb As P Pb Sn Ge Si FON Tl Na Cs Rb K Ba Mg Sr Ca In Ga Al H LiBeBC 4 - 50 Cl H 1.0 0.8 0.9 1.5 1.2 0.7 1.0 2.0 1.5 0.8 1.0 0.9 1.6 1.7 1.8 2.5 1.8 1.9 3.0 2.1 2.0 1.9 3.5 2.5 2.4 2.1 2.0 4.0 3.0 2.8 2.5 2.1

31. 4 - 31 CH110: Chapter 4 polar This unequal sharing results in polar bonds. H Cl Slight positive side Smaller electronegativity Slight positive side Smaller electronegativity Slight negative Larger electronegativity Slight negative Larger electronegativity ++++ ++++ ---- ---- Bond Polarity, Electronegativity Cl H

32. 4 - 32 CH110: Chapter 4 Bond Polarity, Electronegativity H Cl ++ -- polar This unequal sharing results in polar bonds. Slight positive side Smaller electronegativity Slight positive side Smaller electronegativity Slight negative side Larger electronegativity Slight negative side Larger electronegativity Cl H

33. 4 - 33 CH110: Chapter 4 Cl H H 2.13.0 ---- Polar Covalent ++++ ElectronegativityDifference < 0.5 Nonpolar 0.5-1.7 Polar >1.8 Ionic Bond Polarity, Electronegativity

34. 4 - 34 CH110: Chapter 4 COO Polarity, Shape 3.53.52.5 O=C=O ++++ ---- ---- Polar Covalent Bonds Linear Shape (180 o ) ElectronegativityDifference < 0.5 Nonpolar 0.5-1.7 Polar >1.8 Ionic Nonpolar Compound CO 2

35. 4 - 35 CH110: Chapter 4 Polarity, Shape O=C=O ++++ ---- ---- e-’s in 2 directions = 180 o Linear e-’s in 3 directions = 120 o ++++ ---- Trigonal planar Nonpolar Compound Polar Compound

36. 4 - 36 CH110: Chapter 4 Polarity, Shape C HH H Cl C HH H O HH H-O-H ++++ ++++ ---- ++++ ---- e-’s in 4 directions = 109.5 o Tetrahedral Bent 4 directions = 109.5 o

37. 4 - 37 CH110: Chapter 4 Polarity, Shape N HH H ++++ ---- e-’s in 4 directions = 109.5 o Pyramidal N HH H ++++ ++++

38. 4 - 38 CH110: Chapter 4 Some common geometries e- directions around e- directions around Shape central atom Example___ e- directions around e- directions around Shape central atom Example___ Linear 2 O=C=O Tetrahedral 4 Trigonal Planar 3

39. 4 - 39 CH110: Chapter 4 Tetrahedral electron-pair Geometries Tetrahedral Pyramidal Bent

40. 4 - 40 CH110: Chapter 4 Molecular geometry Molecules have specific shapes. Determined by the number of electron pairs around the central species Bonded and unbonded pairs Geometry affects factors like polarity and solubility.

41. 4 - 41 CH110: Chapter 4 Geometry and polar molecules For a molecule to be polar - must have polar bonds - must have the proper geometry CH 4 non-polar CH 3 Clpolar CH 2 Cl 2 polar CHCl 3 polar CCl 4 non-polar WHY? WHY?

42. 4 - 42 CH110: Chapter 4 Properties of ionic and covalent compounds Ionic compounds Held together by electrostatic attraction Ionic compounds are solids at room temp. Exist as 3-D network of ions Formula is simple average

43. 4 - 43 CH110: Chapter 4 Attractive Forces Ionic Bonds 150 - 3000 kcal mol 150 - 3000 kcal mol Melting Point NaCl 801 o C Na 2 S 920 o C MgF 2 1248 o C Melting Point NaCl 801 o C Na 2 S 920 o C MgF 2 1248 o C

44. 4 - 44 CH110: Chapter 4 Covalent compounds Discrete molecular units Atoms held together by bonds Covalent compounds exist in all states (CO 2 - gas, H 2 O - liquid, SiO 2 - solid) Formula represents atoms in a molecule Properties of ionic and covalent compounds O=O

45. 4 - 45 CH110: Chapter 4 HCl ++++ ---- HCl ++++ ---- Attractive Forces Dipole-Dipole 0.1 - 1 kcal mol 0.1 - 1 kcal mol Melting Point HCl -114 o C CH 3 F -142 o C Melting Point HCl -114 o C CH 3 F -142 o C HCl ++++ ---- HCl ++++ ----

46. 4 - 46 CH110: Chapter 4 FF ++++ ---- F ++++ ---- F Attractive Forces Dispersion Forces 0.01 kcal mol 0.01 kcal mol Melting Point F 2 -220 o C CH 4 -183 o C Melting Point F 2 -220 o C CH 4 -183 o C F ++++ ----F F ++++ ---- F

47. 4 - 47 CH110: Chapter 4 HH O ++++ ++++ ---- HH O ++++ ++++ ---- HH O ++++ ++++ ---- HH O ++++ ++++ ---- Polar Attraction Attractive Forces Hydrogen Bonds

48. 4 - 48 CH110: Chapter 4 Hydrogen Bonding of Water Hydrogen Bonds 5 - 10 kcal mol 5 - 10 kcal mol Melting Point H 2 O 0 o C NH 3 -78 o C Melting Point H 2 O 0 o C NH 3 -78 o C

49. 4 - 49 CH110: Chapter 4 Frozen H 2 O: Slow moving molecules H-Bond in patterns Hydrogen Bonding of Water

50. 4 - 50 CH110: Chapter 4 Freezing Point Depression: Frozen Water: slow molecules form hexagonal rings resulting in crystals Solute particles interfere, causing H 2 O molecules to slow down even more. Thus reducing the temperature.

51. 4 - 51 CH110: Chapter 4 Boiling and melting points Characteristic physical properties. Boiling point Boiling point The temperature at which a liquid is converted to a gas at atmospheric pressure. Melting point Melting point The temperature at which a solid is converted to a liquid.

52. 4 - 52 CH110: Chapter 4 Boiling and melting points Chemical Bond Mp Bp N 2 Nonpolar -210-196 O 2 Nonpolar -219-183 NH 3 Polar -78 -33 H 2 O Polar 0 100 Ionic NaCl Ionic 804 ? Melting and Boiling points Very high for ionic compounds Typically lower for covalent compounds

53. 4 - 53 CH110: Chapter 4 Polarity and solubility Solubility SolubilityThe maximum amount of a solute that dissolves in a given solvent Depends on the forces of attraction between molecules - intermolecular Types of intermolecular attractions most often encountered Dipole-Dipole Dipole-Dipole Hydrogen bonding Hydrogen bonding Van der Wall forces Van der Wall forces Like dissolves like General rule“Like dissolves like”