Catalyst – October 8-3, 2010

1. Catalyst – October 8-3, 2010 Label each of the following compounds/descriptions as either IONIC (I) or COVALENT (C). • NaBr • Low melting point • Good conductor, crystal • NO2 • Electrons shared

2. Today’s Agenda • Catalyst • Multiple Covalent Bonds • Pause for Environmental Issues/Activist Letters…DHMO...Oh no! • Let’s see what you know…Naming Covalent Compounds • Work Time • Exit Question

3. At the end of class… • You will receive… • Quizzes • Project Grades • Progress Reports • Quiz Averages… • 3rd Period: 82 • 4th Period: 80 (without curve: 70)

4. Today’s Objectives • SWBAT draw Lewis Dot Structures for covalent compounds with multiple covalent bonds. • SWBAT name and write formulas for covalent compounds.

5. Multiple Covalent Bonds

6. LDS and Multiple Covalent Bonds Key Point #1: Sometimes atoms must share more than one pair of electrons in order to become stable. • This results in double and triple bonds.

7. Double and Triple Bonds • Double covalent bond: two pairs of shared electrons (four electrons) • Triple covalent bond: three pairs of shared electrons (six electrons) = =

8. Strengths of Bonds • Triple • Double • Single Key Point #2: Bond strength increases with number of bonds. So….a double bond is stronger than a single bond, and a triple bond is stronger than a single or double bond.

9. Example: Oxygen • Two oxygen atoms show up at the Homecoming Dance. Each oxygen atom has $6, but it costs $8 per atom to go inside. The School of Elements is offering a discount for couples. It costs only $12 for a couple atoms to go inside. How can both atoms get inside if they each only have $6??? • They can share…electrons that is!!!

10. Try this one: Nitrogen • Two nitrogen atoms show up at the Halloween Party. Each nitrogen atom has $5, but it costs $8 per atom to go inside. The School of Elements is offering a discount for couples. It costs only $10 for a couple atoms to go inside. How can both atoms get inside if they each only have $5??? • Model the bond formation of this happy couple!

11. Steps for Multiple Bond LDS’s • Write formula • Number of valence electrons (ve-) • Number of octet electrons (oe-) • Number of bonds • Draw!

12. More Examples O2 CO2 CO COCl2

13. Catalyst! Draw the covalent bond formation for these atoms CS2 NOBr Extra: SO2 C2Br6 Se2 SiSBr2

14. Practice Time! • SO2 • C2Br6 • Se2 • SiSBr2 • Ge2H4 • OS

15. The Environment… • In this class, I want you to learn the contents of basic chemistry… • However, I also want you to be able to understand the importance of chemistry in the environment. • There is a chemical, DHMO, that is especially ruining our environment in many ways… and something must be done. • You should have already letters to the government to help ban this awful, awful chemical

16. Surprise…. • I have some DHMO with me today. • Does anyone want to see it??

17. Naming Covalent Compounds

18. IONIC 2 ions come together! Metal + Nonmetal COVALENT No ions! Nonmetal + Nonmetal Differences between ionic and covalent Examples: Na1+ + O2- CO2

19. Naming Ionic and Covalent Compounds Key Point #3: When naming compounds, you must know which rules to use (ionic or covalent). • Ionic: Metal + Nonmetal • Covalent: Nonmetal + Nonmetal

20. IONIC Metal + Nonmetal Writing Formulas: Kriss Kross charges Naming: 2nd element ends in –ide, ignore subscripts COVALENT Nonmetal + Nonmetal Writing Formulas: Prefixes = subscript #s Naming: Use prefixes, 2nd element ends in -ide Yo Yo! Let’s break it down!

21. Naming Ionic Compounds • A compound made from Lithium and Oxygen • How do we know if it is ionic or covalent? • Metals and non-metals make ionic compounds

22. Ion: Li Ion: O Ionic Bond Li O

23. Ion: Li Ion: O Ionic Bond Li+ O2-

24. Ion: Li Ion: O Ionic Bond Li+ O2-

25. Cation: Li Anion: O Ionic Bond Li2O

26. MgO Naming Ionic Compounds

27. MgO Magnesium Oxide Naming Ionic Compounds

28. CaCl2 Naming Ionic Compounds

29. CaCl2 Calcium Chloride Naming Ionic Compounds

30. Al2O3 Naming Ionic Compounds

31. Al2O3 Aluminum Oxide Naming Ionic Compounds

32. Naming covalent compounds No Kriss Krossing!

33. PCl3 Naming Covalent Compounds

34. How do we know if this is a covalent compound? • Is it between a metal and a non-metal? • NO!!! Then, it is not ionic!!! • Is it between a non-metal and a non-metal? • YES!!! Then, it is covalent!

35. Rule 1: If the first element has more than one atom, give it a prefix. Naming Covalent Compounds

36. 1 – mono- 2 – di- 3 – tri- 4 – tetra- 5 – penta- 6 – hexa- 7 – hepta- 8 – octa- 9 – nona- 10 – deca- Naming Covalent Compounds

37. PCl3 Naming Covalent Compounds

38. PCl3 Phosphorous Naming Covalent Compounds

39. Rule 2: The second element always gets a prefix, uses the root of the word and ends in -ide. Naming Covalent Compounds

40. PCl3 Phosphorous Naming Covalent Compounds

41. PCl3 Phosphorous Trichloride Naming Covalent Compounds

42. Rule 3: The “o” or “a” at the end of the prefix is dropped if the element begins in a vowel. Naming Covalent Compounds

43. N2O Naming Covalent Compounds

44. Rule 1: If the first element has more than one atom, give it a prefix. Naming Covalent Compounds

45. N2O Dinitrogen Naming Covalent Compounds

46. Rule 2: The second element always gets a prefix, uses the root of the word and ends in -ide. Naming Covalent Compounds

47. N2O Dinitrogen Monooxide Naming Covalent Compounds

48. Rule 3: The “o” or “a” at the end of the prefix is dropped if the element begins in a vowel. Naming Covalent Compounds

49. N2O Dinitrogen Monooxide Naming Covalent Compounds

50. N2O Dinitrogen Monoxide Naming Covalent Compounds