1. Naming and Formula Writing What’s in a name?

2. Quick Review What do metals want to do? –So what do they become? What do nonmetals want to do? –So what do they become? What do opposites do?

3. Naming Ions Ionic Compounds –Consist of a (+) metal ion and a (-) nonmetal ion combined in a proportion such that their charges add up to 0.

4. Monatomic Ions Consist of a single ion with a positive or negative charge resulting from the loss or gain of one or more valence electrons

6. Cations When the metals in groups 1A, 2A, 3A lose electrons, they form cations with positive charges that equal their group number. Their names are the same as the metal followed by “ion” or “cation”

7. Anions Nonmetals tend to gain electrons to form anions, so the charge of a nonmetallic ion is negative.

8. Anions- Naming Anion names start with the stem of the element name and end in –ide F - = –Fluoride N 3- = –Nitride The majority of elements in groups 4A and 8A usually do not form ions. –Why?

9. Oxidation Numbers Found in the upper right-hand corner of the element’s box in the Periodic Table These numbers indicate what the element tends to do with electrons when bonding

10. Oxidation Number Rules 1.For an atom alone or bonded to itself (diatomics), the oxidation number for each of those atoms is 0.

11. Oxidation Number Rules 2.For a simple ion, the oxidation number is its charge (given in the Periodic Table) chloride= aluminum ion= oxide= barium ion= fluoride= potassium ion= sulfide= iron (II)= carbide= manganese (IV)=

12. Oxidation Number Rules 3.Oxygen usually has an oxidation number of -2. CaO= Exceptions: When bonding with fluoride (which is more EN), oxygen is forced to donate electrons, becoming +2  OF 2 In peroxides, like hydrogen peroxide, each oxygen has a -1 oxidation number: H 2 +1 O 2 -1 (peroxide is a polyatomic ion)

13. Oxidation Number Rules 4. Hydrogen usually has an oxidation number of +1. H 2 O= Exception: Metal hydrides. When hydrogen bonds with a group 1 or group 2 metal its oxidation is -1 NaH= Why?

14. Oxidation Number Rules 5. The sum of all the oxidation numbers in a neutral compound must add up to zero. NaCl= 6. The sum of all the oxidation numbers in a polyatomic ion must add up to equal the charge of the ion. CO 3 -2 =

15. Ions of Transition Metals Many form more than one cation with different ionic charges. The charges of the cations of many transition metal ions must be determined by the number of electrons lost. Ex. Fe 2+ and Fe 3+

16. Two methods of naming: 1.STOCK SYSTEM (preferred) A Roman numeral in parentheses is placed after the name of the element to indicate the numerical value of the charge. Fe (II)- “iron two ion” Fe (III)- “iron three ion” 2.Use a ROOT WORD with different suffixes ferr- -ous (II) -ic (III)

17. Some Transition Metals…. Have only 1 ionic charge: –Ag + –Cd 2+ –Zn 2+ we like these because they’re easy!

18. Polyatomic Ions Composed of more than one atom Tightly bound group of atoms that behaves as a unit and carries a charge Names of most p.i. end in –ite or –ate Atoms in polyatomics are sharing electrons

19. Three important ions have different endings: NH 4 + = ammonium CN - = cyanide OH - = hydroxide

20. -ites and -ates Sulfite: SO 3 2- Nitrite: NO 2 - Chlorite: ClO 2 - ONE LESS OXYGEN ATOM Sulfate: SO 4 2- Nitrate: NO 3 - Chlorate: ClO 3 - ONE MORE OXYGEN ATOM

21. Polyatomics with hydrogen Think of H representing a hydrogen ion (H + ) combined with another polyatomic ion H + + CO 3 2-  HCO 3 - (hydrogen carbonate) H + + PO 4 3-  HPO 4 2- (hydrogen phosphate) H + + HPO 4 2-  H 2 PO 4 - (dihydrogen phosphate)

22. COMPOUNDS Early things named by people who discovered them- usually based on properties: –Ex. NaHCO 3 = baking soda

23. Binary Compound Is composed of two elements and can either be either ionic or molecular (covalent)

24. Antoine-Laurent Lavoisier Determined the composition of many substances. Worked with other chemists to develop a systematic method for naming chemical compounds.

25. Compound: M + and NM - You must make sure that the compound is composed of a monatomic metallic cation and monatomic nonmetallic anion. Name the cation first, followed by the anion.

26. Cs 2 O cesium oxide

27. NaBr sodium bromide

28. SrF 2 strontium fluoride

29. What about compounds with elements that form multiple ions? CuO Cu + O 2- Cu 2+ copper (II) oxide

30. Examples FeO Fe 2 O 3 Mn 2 O 7

31. Compounds- FORMULAS Write the symbol of the cation and then the anion. Add whatever subscripts are needed to balance the charges (compounds must be neutral) K + + Cl -  KCl

32. Criss-Cross Method Fe 3+ O 2- Fe 2 O 3 Charge on one element becomes subscript on other, and vice versa 2(3+) + 3(2-) = 0 iron (II) oxide

33. Ca 2+ S 2- CaS Charges balance 1:1 ratio Calcium sulfide

34. Compounds with Polyatomic Ions Write the symbol for the cation followed by the formula for the polyatomic ion and balance the charges. Ca 2+ (NO 3 ) 1- Ca(NO 3 ) 2 calcium nitrate

35. Naming Compounds with Polyatomic Ions You must first recognize that the compound contains a polyatomic ion. State the cation first and then the anion just as you did in naming other compounds. –LiCN= lithium cyanide –NaClO= sodium hypochlorite

36. A little different… Some compounds containing polyatomic ions do not include a metal. They have the ammonium cation instead. –NH 4 + EXAMPLE: NH 4 CH 3 COO –Ammonium acetate

37. Compounds: NM + NM 2 nonmetals

38. Naming NM + NM Compounds The prefix tells how many atoms of each element are present in a molecule of a compound

39. Prefixes you must know Mono- 1 Di- 2 Tri- 3 Tetra- 4 Penta- 5 Hexa- 6 Hepta- 7 Octa- 8 Nona- 9 Deca- 10

40. Still on nonmetal compounds Names all end in -ide N 2 O- dinitrogen monoxide (laughing gas)

41. Rules 1.Confirm that the compound contains 2 nonmetals 2.Name the elements in the order listed in the formula 3.Use the prefixes to indicate the number of each kind of atom 4.Omit the prefix mono- when the formula contains only one kind of the first element in the name Carbon monoxide (CO)

42. Example Cl 2 O 8 dichlorine octoxide

43. Formulas Use the prefixes in the name to tell you the subscripts of each element in the formula. Then write the correct symbols for the two elements with the appropriate subscripts. Phosphorus pentafluoride –PF 5 Dinitrogen tetroxide –N2O4–N2O4

44. ACIDS Acid- a compound that contains one or more hydrogen atoms and produces hydrogen ions when dissolved in water. Consider the acid to consist of an anion combined with as many hydrogen atoms are needed to make the molecule electrically neutral. H n X (where X is a mono or polyatomic anion)

45. Acids- Three Rules 1.When the name of the anion ends in -ide: the acid name begins with the prefix hydro-. The stem of the anion has the suffix -ic and is followed by the word ACID. EXAMPLE- HCl= hydrochloric acid

46. Acids- Three Rules 2.When the anion name ends in –ite: the acid name is the stem of the anion with the suffix -ous followed by the word ACID. EXAMPLE- H 2 SO 3 - sulfurous acid

47. Acids- Three Rules 3.When the anion name ends in –ate: the acid name is the stem of the anion with the suffix -ic followed by the word ACID EXAMPLE- HNO 3 - nitric acid

48. Acids- Formulas Use the rules for writing the names of acids in reverse to write the formulas for acids Hydrobromic acid = –HBr Phosphorous acid = –H 3 PO 3

49. BASES Base- an ionic compound that produces hydroxide ion when dissolved in water. Bases are named the same way as other compounds that contain a M + and NM - (or polyatomic)- –The name of the cation is followed by the name of the anion. Aluminum hydroxide –Al(OH) 3

50. The Law of Definite Proportions In samples of any chemical compound, the masses of the elements are always in the same proportions.

51. The Law of Multiple Proportions Whenever the same two elements form more than one compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers.

52. Some reminders 1.An -ide ending generally indicates a binary compound (TWO ELEMENTS) 2.An -ite or -ate ending means a polyatomic ion that includes oxygen in the formula 3.Prefixes in a name generally indicate that the compound is made of two or more nonmetals 4.A roman numeral after the name of a cation shows the ionic charge of the cation