1. Read section 9.3 (pages 252- 255) in the textbook and do problems 30-34 on page 255. Check your answers in the back of the book, on page 926. Homework

2. Daily Quiz 250

3. Name these molecules: Name these acids: Daily Quiz 250

4. Name these molecules: 1.NO 2 2.N 2 O Name these acids: 3.H 3 P 4.H 3 PO 4 Daily Quiz 250

5. Name these molecules: 1.NO 2 nitrogen dioxide 2.N 2 O Name these acids: 3.H 3 P 4.H 3 PO 4 Daily Quiz 250

6. Name these molecules: 1.NO 2 nitrogen dioxide 2.N 2 Odinitrogen monoxide Name these acids: 3.H 3 P 4.H 3 PO 4 Daily Quiz 250

7. Name these molecules: 1.NO 2 nitrogen dioxide 2.N 2 Odinitrogen monoxide Name these acids: 3.H 3 Phydrophosphoric acid 4.H 3 PO 4 Daily Quiz 250

8. Name these molecules: 1.NO 2 nitrogen dioxide 2.N 2 Odinitrogen monoxide Name these acids: 3.H 3 Phydrophosphoric acid 4.H 3 PO 4 phosphoric acid Daily Quiz 250.

9. Molecular Structures

10. NH 3

11. Molecular Structures Step 1a: Hydrogen is always terminal (at the end) It can only form one bond. NH 3

12. Molecular Structures Step 1b: The atom with the least attraction for electrons is in the middle. Usually this atom is towards the left side of the periodic table NH 3

13. Molecular Structures Step 1b: The atom with the least attraction for electrons is in the middle. Usually this atom is towards the left side of the periodic table. H N H H

14. Molecular Structures Step 2: Count all the valance electrons (electrons in the outer shells) H N H H

15. Molecular Structures Step 2: Count all the valance electrons (electrons in the outer shells) H N H H 11 1 5

16. Molecular Structures Step 2: Count all the valance electrons (electrons in the outer shells). 1 + 1 + 1 + 5 = 8 H N H H 11 1 5

17. Molecular Structures Step 3: Divide by two to find the number of bonding pairs of electrons H N H H 8

18. Molecular Structures Step 3: Divide by two to find the number of bonding pairs of electrons. 8 ÷ 2 = 4 H N H H

19. Molecular Structures Step 4: Put one bonding pair (a single bond) between the central atom and each terminal atom H N H H 4

20. Molecular Structures Step 5: How many pairs of electrons do you still have left? H N H H 4

21. Molecular Structures Step 5: How many pairs of electrons do you still have left? H N H H 4 – 3 = 1

22. Molecular Structures Step 5: How many pairs of electrons do you still have left? Add these to the terminal atom first, then the central atom H N H H 4 – 3 = 1

23. Molecular Structures Step 5: How many pairs of electrons do you still have left? Add these to the terminal atom first, then the central atom. H N H H This is called a “lone pair”

24. Molecular Structures Step 6: Are you done? H N H H

25. Molecular Structures Step 6: Are you done? Count the electrons associated with each atom H N H H

26. Molecular Structures Step 6: Are you done? Count the electrons associated with each atom. H N H H 2 22 2

27. Molecular Structures Step 6: If they add up to eight (or two for H), then you’re done 2 + 2 + 2 + 2 + 8 H N H H 2 22 2

28. Molecular Structures Step 6: If they add up to eight (or two for H), then you’re done. If they don’t add up to eight, you need to take a lone pair from one of the terminal atoms to make a double or triple bond.

29. Molecular Structures Remember: Hydrogen atoms want 2 electrons

30. Molecular Structures Remember: Hydrogen atoms want 2 electrons Most other atoms want 8 electrons

31. Molecular Structures Remember: Hydrogen atoms want 2 electrons Most other atoms want 8 electrons Polyatomic ions will have extra electrons (if they’re negative) or fewer (if they’re positive).

32. Molecular Structures Let’s try another… CO 2

33. Molecular Structures Step 1: CO 2

34. Molecular Structures Step 1: Hydrogens terminal Leftmost element central CO 2

35. Molecular Structures Step 1: Hydrogens terminal Leftmost element central O C O

36. Molecular Structures Step 2: O C O

37. Molecular Structures Step 2: Count valence electrons O C O

38. Molecular Structures Step 2: Count valence electrons O C O 466

39. Molecular Structures Step 2: Count valence electrons 6 + 4 + 6 = 16 O C O 466

40. Molecular Structures Step 3: 16 valence electrons O C O

41. Molecular Structures Step 3: Count pairs of electrons 16 valence electrons O C O

42. Molecular Structures Step 3: Count pairs of electrons 16 ÷ 2 = 8 O C O

43. Molecular Structures Step 4: 8 pairs of electrons O C O

44. Molecular Structures Step 4: Put bonds between atoms 8 pairs of electrons O C O

45. Molecular Structures Step 4: Put bonds between atoms 8 pairs of electrons O C O

46. Molecular Structures Step 5: 8 pairs of electrons O C O

47. Molecular Structures Step 5: How many left? Add to terminal, then to central. 8 pairs of electrons O C O

48. Molecular Structures Step 5: How many left? Add to terminal, then to central. 8 – 2 = 6 O C O

49. Molecular Structures Step 5: How many left? Add to terminal, then to central. 8 – 2 = 6 O C O

50. Molecular Structures Step 5: How many left? Add to terminal, then to central. 8 – 2 = 6 O C O

51. Molecular Structures Step 5: How many left? Add to terminal, then to central. 8 – 2 = 6 O C O

52. Molecular Structures Step 5: How many left? Add to terminal, then to central. 8 – 2 = 6 O C O

53. Molecular Structures Step 5: How many left? Add to terminal, then to central. 8 – 2 = 6 O C O

54. Molecular Structures Step 5: How many left? Add to terminal, then to central. 8 – 2 = 6 O C O

55. Molecular Structures Step 6: O C O

56. Molecular Structures Step 6: Are we done yet? O C O

57. Molecular Structures Step 6: Are we done yet? O C O 2 2 2 2

58. Molecular Structures Step 6: Are we done yet? O C O 2 2 2 2 √

59. Molecular Structures Step 6: Are we done yet? O C O 22 √

60. Molecular Structures Step 6: Are we done yet? O C O 22 √ x

61. Molecular Structures Step 6: Are we done yet? O C O 2 2 √ x 2 2 √

62. Molecular Structures Step 6: Are we done yet? O C O 2 2 √ x 2 2 √

63. Molecular Structures Step 6: Are we done yet? O C O √ x √

64. Molecular Structures Step 6: Are we done yet? Take lone pairs to make multiple bonds O C O √ x √

65. Molecular Structures Step 6: Are we done yet? Take lone pairs to make multiple bonds O C O √ x √

66. Molecular Structures Step 6: Are we done yet? Take lone pairs to make multiple bonds O C O √ x √

67. Molecular Structures Step 6: Are we done yet? Take lone pairs to make multiple bonds O C O √ x √ 2 22 2

68. Molecular Structures Step 6: Are we done yet? Take lone pairs to make multiple bonds O C O √ √ √ 2 22 2

69. Molecular Structures Step 6: Are we done yet? Take lone pairs to make multiple bonds O C O √ √ √

70. Molecular Structures Step 6: Are we done yet? Take lone pairs to make multiple bonds O C O √ √ √

71. Read section 9.3 (pages 252- 255) in the textbook and do problems 30-34 on page 255. Check your answers in the back of the book, on page 926.. Homework