1 / 59

Chapter 16 Covalent Bonding

Chapter 16 Covalent Bonding. Milbank High School. Section 16.1 The Nature of Covalent Bonding. OBJECTIVES: Describe and give examples of coordinate covalent bonding, resonance structures, and exceptions to the octet rule. Section 16.1 The Nature of Covalent Bonding. OBJECTIVES:

luella
Download Presentation

Chapter 16 Covalent Bonding

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 16Covalent Bonding Milbank High School

  2. Section 16.1The Nature of Covalent Bonding • OBJECTIVES: • Describe and give examples of coordinate covalent bonding, resonance structures, and exceptions to the octet rule.

  3. Section 16.1The Nature of Covalent Bonding • OBJECTIVES: • Use electron dot structures to show the formation of single, double, and triple covalent bonds.

  4. + + How does H2 form? • The nuclei repel

  5. + + How does H2 form? • The nuclei repel • But they are attracted to electrons • They share the electrons

  6. Covalent bonds • Nonmetals hold on to their valence electrons. • Get noble gas configuration by sharing valence electrons with each other. • By sharing, both atoms get to count the electrons toward a noble gas configuration.

  7. F Covalent bonding • Fluorine has seven valence electrons

  8. F F Covalent bonding • Fluorine has seven valence electrons • A second atom also has seven

  9. F F Covalent bonding • Fluorine has seven valence electrons • A second atom also has seven • By sharing electrons…

  10. F F Covalent bonding • Fluorine has seven valence electrons • A second atom also has seven • By sharing electrons…

  11. F F Covalent bonding • Fluorine has seven valence electrons • A second atom also has seven • By sharing electrons…

  12. F F Covalent bonding • Fluorine has seven valence electrons • A second atom also has seven • By sharing electrons…

  13. F F Covalent bonding • Fluorine has seven valence electrons • A second atom also has seven • By sharing electrons…

  14. F F Covalent bonding • Fluorine has seven valence electrons • A second atom also has seven • By sharing electrons… • …both end with full orbitals

  15. Covalent bonding • Fluorine has seven valence electrons • A second atom also has seven • By sharing electrons… • …both end with full orbitals F F 8 Valence electrons

  16. Covalent bonding • Fluorine has seven valence electrons • A second atom also has seven • By sharing electrons… • …both end with full orbitals F F 8 Valence electrons

  17. A Single Covalent Bond is... • A sharing of two valence electrons. • Only nonmetals and Hydrogen. • Different from an ionic bond because they actually form molecules.

  18. H O Water Each hydrogen has 1 valence electron Each hydrogen wants 1 more The oxygen has 6 valence electrons The oxygen wants 2 more They share to make each other happy

  19. O Water • The oxygen still wants one more H

  20. O Water • The second hydrogen attaches • Every atom has full energy levels H H Sample 16-1, p.440

  21. Multiple Bonds • Double bonds - share two pairs (4 total) of electrons • Triple bond - share three pairs (6 total) of electrons • Table 16.1, p.443 - Know which elements are diatomic (Oxygen?)

  22. O Carbon dioxide • CO2 - Carbon is central atom( more metallic ) • Carbon has 4 valence electrons • Wants 4 more • Oxygen has 6 valence electrons • Wants 2 more C

  23. O Carbon dioxide • Attaching 1 oxygen leaves the oxygen 1 short, and the carbon 3 short C

  24. O O Carbon dioxide • Attaching the second oxygen leaves both oxygen 1 short and the carbon 2 short C

  25. O O Carbon dioxide • The only solution is to share more C

  26. O O Carbon dioxide • The only solution is to share more C

  27. O Carbon dioxide • The only solution is to share more O C

  28. O Carbon dioxide • The only solution is to share more O C

  29. O Carbon dioxide • The only solution is to share more O C

  30. Carbon dioxide • The only solution is to share more O C O

  31. Carbon dioxide • The only solution is to share more • Requires two double bonds • Each atom can count all the electrons in the bond O C O

  32. Carbon dioxide • The only solution is to share more • Requires two double bonds • Each atom can count all the electrons in the bond 8 valence electrons O C O

  33. Carbon dioxide • The only solution is to share more • Requires two double bonds • Each atom can count all the electrons in the bond 8 valence electrons O C O

  34. Carbon dioxide • The only solution is to share more • Requires two double bonds • Each atom can count all the electrons in the bond 8 valence electrons O C O

  35. Examples • Draw in the bonds • All 8 electrons are accounted for • Everything is full H H N H

  36. HCN • Put single bond between each atom • Need to add 2 more bonds • Must go between C and N H C N

  37. HCN • Put in single bonds • Need 2 more bonds • Must go between C and N • Uses 8 electrons - 2 more to add to equal the 10 it has H C N

  38. HCN • Put in single bonds • Need 2 more bonds • Must go between C and N • Uses 8 electrons - 2 more to add • Must go on N to fill octet H C N

  39. Another way of indicating bonds • Often use a line to indicate a bond • Called a structural formula • Each line is 2 valence electrons H O H H O H =

  40. Structural Examples • C has 8 e- because each line is 2 e- • same for N • same for C here • same for O H C N H C O H

  41. C O A Coordinate Covalent Bond... • When one atom donates both electrons in a covalent bond. • Carbon monoxide • CO

  42. Coordinate Covalent Bond • When one atom donates both electrons in a covalent bond. • Carbon monoxide • CO C O

  43. Coordinate Covalent Bond • When one atom donates both electrons in a covalent bond. • Carbon monoxide • CO C O Shown as: C O

  44. Bond Dissociation Energies... • The total energy required to break the bond between 2 covalently bonded atoms • High dissociation energy usually means unreactive • Table 16.3, p448 • Sample: Calculate the kJ to dissociate the bonds in 0.5 mol CO2

  45. Resonance is... • When more than one valid dot diagram is possible. • Consider the two ways to draw ozone (O3)

  46. Exceptions to Octet rule • When there is an odd number of valence electrons • NO2 has 17 valence electrons, because the N has 5, and each O contributes 6 • impossible to satisfy octet, yet the stable molecule does exist

  47. Section 16.2Bonding Theories • OBJECTIVES: • Describe the molecular orbital theory of covalent bonding, including orbital hybridization.

  48. Section 16.2Bonding Theories • OBJECTIVES: • Use VSEPR theory to predict the shapes of simple covalently bonded molecules.

  49. VSEPR: stands for... • Valence Shell Electron Pair Repulsion • Predicts three dimensional geometry of molecules. • The name tells you the theory: • Valence shell - outside electrons. • Electron Pair repulsion - electron pairs try to get as far away as possible. • Can determine the angles of bonds.

  50. VSEPR • Single bonds fill all atoms. • There are 4 pairs of electrons pushing away. • The furthest they can get away is 109.5º H H C H H

More Related