1 / 53

Chemical Bonding

Chemical Bonding. Ionic, Covalent, and Metallic Bonding. Properties of Covalent Compounds. ARE MOLECULAR…SMALLEST UNIT IS A MOLECULE USUALLY FORM BETWEEN TWO NONMETALS NONMETALLIC MAY BE SOLID, LIQUID OR GAS LOW MELTING POINT. HIGH TO LOW SOLUBILITY IN WATER DEPENDING ON POLARITY

nero-henson
Download Presentation

Chemical 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. Chemical Bonding Ionic, Covalent, and Metallic Bonding

  2. Properties of Covalent Compounds

  3. ARE MOLECULAR…SMALLEST UNIT IS A MOLECULE • USUALLY FORM BETWEEN TWO NONMETALS • NONMETALLIC • MAY BE SOLID, LIQUID OR GAS • LOW MELTING POINT

  4. HIGH TO LOW SOLUBILITY IN WATER DEPENDING ON POLARITY • SOLIDS ARE SOFTER THAN IONIC SOLIDS • NONPOLAR COMPOUNDS DO NOT CONDUCT WHEN MOLTEN OR DISSOLVED. POLAR COMPOUNDS MAY CONDUCT WHEN DISSOLVED IN WATER • EXAMPLES: • SUGAR • WAX • ALCOHOL • IODINE

  5. Properties of Ionic Compounds

  6. COMPOSED OF POSITIVE AND NEGATIVE IONS • SMALLEST PARTICLE IS AN ION • FORM BETWEEN A METAL (+) AND A NONMETAL(-) • ALL ARE CRYSTALLINE SOLIDS • ARE ARRANGED IN AN ORDERLY FASHION TO FORM CRYSTALS

  7. HIGH MELTING POINTS • BRITTLE • HARD • CONDUCT WHEN MELTED OR DISSOLVED • EXAMPLES: • TABLE SALT • LYE (SODIUM HYDROXIDE) • POTASSIUM NITRATE

  8. Properties of Metals

  9. LUSTER • MALLEABILLITY • DUCTILITY • CRYSTALLINE • SOLIDS AT ROOM TEMP. EXCEPT FOR MERCURY (Hg)

  10. MELTING POINTS VARY WIDELY • GOOD CONDUCTORS OF HEAT& ELECTRICITY • Examples: • Gold • Iron • Silver • Copper

  11. Predicting Bond Types Based on Compounds and Electronegativity

  12. IONIC BONDS OCCUR WHEN ELECTRONEGATIVITY DIFFERENCES BETWEEN THE TWO ATOMS ARE GREATER THAN 1.7 • METALS LOSE ELECTRONS AND FORM + IONS • NONMETALS GAIN ELECTRONS AND FORM - IONS • COVALENT BONDS FORM WHEN TWO ATOMS SHARE ELECTRONS • NONPOLAR COVALENT BOND---EQUAL SHARING--- • EN = 0.4 OR LESS • POLAR COVALENT BOND---UNEQUAL SHARING--- • EN = 0.41- 1.67

  13. IONIC BONDING OCCURS BETWEEN A METAL AND A NONMETAL • COVALENT BONDING OCCURS BETWEEN 2 NONMETALS • NONPOLAR • OCCURS BETWEEN 2 ATOMS OF THE SAME NONMETAL • POLAR • OCCURS BETWEEN 2 DIFFERENT NONMETALS • METALLIC BONDING OCCURS BETWEEN 2 METALS

  14. PREDICTING BOND TYPE PRACTICE USING ELECTRONEGATIVITY (chart pg. 169) AND COMPOUNDS

  15. What type of bond is represented by KF? • Electronegativity • F: 4.0 • K: 0.8 4.0-0.8= 3.2 • Compounds • K: metal • F: nonmetal IONIC BOND

  16. What type of bond is represented by O2? • Electronegativity • O: 3.5 • O: 3.5 3.5-3.5=0 • Compounds • O: nonmetal • O: nonmetal NONPOLAR COVALENT BOND

  17. What type of bond is represented by ICl? • Electronegativity • I: 2.5 • Cl: 3.0 3.0-2.5= 0.5 • Compounds • I: nonmetal • Cl: nonmetal POLAR COVALENT BOND

  18. What type of bond is represented by K2? • Compounds • K: metal • K: metal METALLIC BOND

  19. OH N2 HF CO NaCl H2 MgO AlCl3 9. CH4 10. NF3 11. CS2 12. CCl4 13. SO3 14. Na2 15. Cl2 Using your notes, predict the bond type of the following compounds as either ionic, polar covalent, nonpolar covalent, or metallic:

  20. IONS

  21. Octet Rule States that atoms lose, gain or share electrons in order to acquire a full set of eight valence electrons (the stable electron configuration of a noble gas).

  22. Ions • An atom or bonded group of atoms with a positive or negative charge • CATIONS (Positive Ions) • Low electronegativity; willing to give up electrons • Formed by metals losing electrons or giving electrons to nonmetals • Losing electrons result in positive charges • ANIONS (Negative Ions) • High electronegativity; electron loving • Formed by nonmetals gaining electrons from metals • Gaining electrons result in a negative charge

  23. Determining the Ion • Determine the number of valence electrons • Draw Lewis Dot Structure • Determine whether it would be easier to give away electrons or gain electrons • Trying to attain 8 electrons or a full shell • Write the charge of the element based on the number of electrons gained or lost • Gaining electrons = - charge • Losing electrons = + charge

  24. Gaining or Losing Electrons • Any element with 4 or less valence electrons will give away their electrons Losing electrons = positive charge • Any element with 5-7 valence electrons will steal electrons Gaining electrons = negative charge

  25. K Al S Mg O F Cu Ca Practice

  26. Day 2

  27. Ionic Bonding

  28. CHEMICAL BONDS RESULTING FROM ELECTROSTATIC ATTRACTION BETWEEN POSITIVE AND NEGATIVE IONS • REQUIRE THE LOST OF ELECTRON(S) BY ATOMS OF LOW ELECTRONEGATIVITY (METALS) TO ATOMS OF HIGH ELECTRONEGATIVITY(NONMETALS) • REQUIRE AN ELECTRONEGATIVITY DIFFERENCE GREATER THAN 1.7

  29. Examples • NaCl • MgO • AlCl3 • CCl4

  30. Draw the Lewis structure of each element Circle the element donating electrons Underline the element receiving the electrons Draw the arrow(s) to show the transfer of electrons Write each element as an ion KF MgI BeS NaO AlBr LiBr BaS CsP Ionic Bonding Practice

  31. Metallic Bonding

  32. RESULTS FROM THE ATTRACTION BETWEEN METAL ATOMS AND THE SURROUNDING SEA OF ELECTRONS • FORMS BETWEEN 2 METAL ATOMS • BONDING ELECTRONS ARE DELOCALIZED ALONG EMPTY P OR D ORBITALS • STRENGTH OF BOND VARIES WITH NUCLEAR CHARGE OF THE METAL

  33. Covalent Bonding

  34. FORMS WHEN A PAIR OF E- ARE SHARED • FORM MOLECULES • SHARING MAY BE EQUAL…NONPOLAR OR UNEQUAL…POLAR • SINGLE COVALENT BOND FORMS WHEN TWO ATOMS SHARE A PAIR OF E-

  35. DOUBLE COVALENT BOND FORMS WHEN 2 ATOMS SHARE 2 PAIRS OF E- • TRIPLE COVALENT BOND FORMS WHEN 2 ATOMS SHARE 3 PAIRS OF E- • SIGMA BOND…FORMED BY DIRECT OVERLAP OF TWO ORBITALS • PI BOND…FORM WHEN 2 P ORBITALS OVERLAP SIDE-TO-SIDE WITH THEIR AXIS PARALLEL

  36. SINGLE BOND IS ALWAYS A SIGMA BOND • DOUBLE BOND CONSISTS OF ONE SIGMA BOND AND ONE PI BOND • TRIPLE BOND CONSISTS OF ONE SIGMA BOND AND TWO PI BONDS • ONLY 4 ELEMENTS COMMONLY FORM DOUBLE OR TRIPLE BONDS: C, S, N, O

  37. Examples of Covalent Bonds HCl

  38. Diatomic: 2 atoms Prefix di means 2 Occur in nature as diatomic molecules instead of single atoms because they are more stable than individual atoms Hydrogen (H2) Oxygen (O2) Nitrogen (N2) Fluorine (F2) Chlorine (Cl2) Bromine (Br2) Iodine (I2) Diatomic Gases (7)

  39. Examples of Covalent Bond in Diatomic Molecule Br2

  40. Draw the Lewis structure of each element Circle the electrons being shared Draw each compound HF CCl4 SeI2 H2S NBr3 Covalent Bonding

  41. Homework Textbook pg. 220: 12-16 & pg. 247: 6-10 & 12a-e

  42. Day 3

  43. Molecular Shapes

  44. 3 ways to predict the shape of molecules • Build the model • VSEPR • Valence Shell Electron Pair Repulsion Theory • Hybridization

  45. Building Models Physical Model Computer Generated Model

  46. Hybridization A process in which atomic orbitals are mixed to form new identical hybrids

  47. VSEPR • REPULSION BETWEEN VALENCE ELECTRONS CAUSES ELECTRON PAIRS TO SPREAD AS FAR APART AS POSSIBLE • UNSHARED PAIRS OCCUPY MORE SPACE THAN SHARED PAIRS. • THEORY GIVES SHAPE AND BOND ANGLE. SEE VSEPR CHART pg. 260

  48. Polarity of Molecules • MUST CONTAIN AT LEAST ONE POLAR BOND & BE ASSYMETRIC • ARE CALLED DIPOLES BECAUSE THEY HAVE A POSITIVE END AND A NEGATIVE END • Symmetrical = nonpolar molecule • Asymmetrical = polar molecule

  49. NF3 SiF4 H2Se SeCl2 BF3 GeF4 H2S CF4 SCl2 NH2Cl Draw the following molecules and determine their polarity and shape :

  50. Intermolecular Forces In order of decreasing strength: Hydrogen Bonds Dipole-Dipole Forces London Dispersion Forces

More Related