2. Honors Chapter 9 (and some Chapter 7) Chemical Names and Formulas

7. Chemical formula - combination of symbols that represent the composition of a compound Shows elements present and number of atoms

8. subscripts Represent the number of atoms of that element in the compound No subscript is an “understood” 1

9. NaCl 1 Na 1 Cl H 2 SO 4 2 H 1 S 4 O Ca(ClO 3 ) 2 ????? 1 Ca 2 Cl 6 O

10. Ionic – transfer of electrons Called a “formula unit” Covalent – share electrons called “molecule”

11. IONIC COMPOUNDS  Four different types we will learn about

12. Metal + nonmetal (binary ionic) Metal + polyatomic ion Polyatomic ion + polyatomic ion Polyatomic ion + nonmetal

13.  Monatomic ions – ions consisting of only one atom  Charges can often be determined by using the periodic table  Metallic elements – tend to lose electrons to form cations  Group 1 all 1+  Group 2 all 2+

14.  Nonmetals tend to gain electrons when they bond with metals – form anions

15.  Many have more than one common ionic charge Are going to use roman numerals

17. Oxidation number Indication of how many electrons it will gain or lose when it forms a bond Gains or loses electrons – forms an ion Charged particle Can be found for each element on the periodic table Refer to yours!!!

18. Some elements have more than 1 oxidation number – that means they can form more than one type of compound

19. When a single atom takes on a charge (by gaining or losing electrons) – it forms a “monatomic ion” Ion made up of more than 1 atom – “polyatomic” ion

20. Monatomic ions Na + Ca +2 Cl - O -2 Polyatomic ions CO 3 -2 ClO 3 - OH -

21. Why would an atom want to form an ion? Remember the “octet rule” Wants a filled outer shell For most atoms, that is 8

22. Samples on board using electron dot notation Na and Cl Ca and Cl Al and Cl Ca and S K and N you do

23. 1) Metal + nonmetal Metal always written first – has positive oxidation number (written first) Nonmetal written second – has negative oxidation number

24. Can use “criss-cross” method to arrive at correct formula. Must remember to simplify subscripts if possible!! Magnesium oxide - MgO

25. Naming binary ionic compounds Metal full name first Nonmetal name with “ide” ending NaClsodium chloride CaCl 2 calcium chloride LiFlithium fluoride AlBr 3 aluminum bromide

26. Some metals have multiple oxidation numbers Use Roman numerals to specify the oxidation number used I, II, III, IV, V, VI, VII, VIII Transition metals characteristically have multiple oxidation numbers ONLY USE ROMAN NUMERALS IF THE METAL HAS MORE THAN ONE OXIDATION NUMBER LISTED

27. Nonmetals may have more than one oxidation number, you just use the first number listed - NEGATIVE

28. Examples: Co, Ni, Cu, Fe, Mn Always check before writing name for the compound FeCl 2 Iron(II) chloride FeO Fe 2 O 3

29. Write formulas for the following calcium sulfide strontium bromide chromium(III) chloride iron(II) oxide

30. CaS SrBr 2 CrCl 3 FeO

31. Name the following compounds Fe 2 O 3 KI CuO NiCl 3 CrO 3

32. Iron(III) oxide Potassium iodide Copper(II) oxide Nickel(III) chloride Chromium(VI) oxide

33. 2. Metal + polyatomic ion Almost all polyatomic ions have a negative charge 2 you are responsible for have a positive charge NH 4 + and H 3 O + Polyatomic ions travel as a unit Page 257 list of polyatomic ions

34. NEVER CHANGE THE SUBSCRIPTS IN A POLYATOMIC ION THAT MEANS NEVER!!!!!!!

35. Can use same “criss-cross” method for determining the correct formula Same rules apply – must factor the subscripts if you can (only the oxidation numbers that are used – NOT THE SUBSCRIPTS OF THE POLYATOMIC ION!!!!!!

36. At first, always put a parenthesis around the polyatomic ion Only time the parenthesis can be dropped is if a “1” criss-crosses down or if the subscript factors to a “1”

37. Don’t forget to include a roman numeral in the name if the metal has multiple oxidation numbers!!!!!!

38. Examples on board

39. Naming Metal name first (only use roman numeral if the metal has more than one oxidation number!!!) Second is the name of the polyatomic ion – taken directly from the table!!

40. Don’t make up your own name!!!!!!!!

41. Characteristics of Ionic Compounds Representative unit = “formula unit” Type of elements: Metal with nonmetal Physical state: crystalline solid (hard) High melting point Most are soluble in H 2 O

42. Poor conductors of electricity in the solid state –But good conductors when melted (molten) or dissolved in H 2 O (aq) (ions free to move)

43. Molecular Compounds (covalent) Representative unit – “molecule” (bonded covalently) Type of elements – nonmetals Physical state – solid, liquid, gas – Solids – low melting point, brittle

44. Molecule – electrically neutral group of atoms that act as a unit

45. Naming binary molecular compounds 2 elements in the compound – Both nonmetals! 2 naming systems – Prefix system – Stock system (roman numerals) Both systems are correct I’m sure you will prefer the prefix system!

46. Prefixes you must memorize! Number of Prefix used atoms 1 mono 2 di 3 tri 4 tetra 5 penta 6 hexa 7 hepta 8 octa 9 nona 10 deca

47. When 2 nonmetallic elements combine – Often do so in more than one way – Example CO CO 2 Problem with calling them both “carbon oxide”

48. CO 2 – you exhale. It is normally present in the air you breathe CO – hopefully is not in the air you breathe In large amount R.I.P. Catalytic converter – cars – Converts CO to CO 2

49. Naming binary molecular compounds Prefix + first element name Followed by prefix + 2 nd element name with “ide” ending ****** only time you can neglect a prefix is if the first element in the compound is a single atom

50. PCl 3 phosphorus trichloride CO Carbon monoxide (not monocarbon monoxide!)

51. Don’t use “double vowels” Change if a “tongue twister” Monooxide  monoxide Decaoxide  decoxide Trioxide – is fine

52. N 2 O Dinitrogen monoxide SF 6 Sulfur hexafluoride N 2 H 4 Dinitrogen tetrahydride – NO FACTORING ALLOWED!!!

53. P 2 O 3 Diphosphorus trioxide

54. Name the following : CS 2 Cl 2 O 7 N 2 O 5 CCl 4 CrCl 3

55. Carbon disulfide Dichlorine heptoxide Dinitrogen pentoxide Carbon tetrachloride Chromium III chloride GOTCHA!!!!!

56. Write formulas for the following : carbon tetrabromide dinitrogen tetrahydride boron trichloride diphosphorus trioxide

57. CBr 4 N 2 H 4 BCl 3 P 2 O 3

58. A molecular compounds worksheet just for you!!

59. Network covalent compounds Covalent compounds that are not made up of individual molecules. All the atoms are joined in a covalently bonded three dimensional network No distinct units in these compounds Have very high melting points SiC SiO 2 Si 3 N 4

60. Acids you should know! Oxyacids – contain H, O and a third element (usually a nonmetal) AceticHCH 3 COO (acetate ion) NitricHNO 3 (nitrate ion) NitrousHNO 2 (nitrite ion) PhosphoricH 3 PO 4 (phosphate ion)

61. SulfuricH 2 SO 4 (sulfate ion) SulfurousH 2 SO 3 (sulfite ion) CarbonicH 2 CO 3 (carbonate ion) Hypochlorous HClO (hypochlorite ion) ChlorousHClO 2 (chlorite ion) Chloric HClO 3 (chlorate ion) PerchloricHClO 4 (perchlorate ion)

62.  HF hydrofluoric acid  HCl hydrochloric acid  HBr hydrobromic acid  HIhydroiodic acid