1. Compounds and Bonding:  Unit 5: Notes & Practice  Ionic Compounds & Ionic Bonds  How to write formulas for Ionic Compounds  How to write names for Ionic Compounds

2.  Nomenclature: an organized system for naming  Compounds: 2 or more elements chemically combined (bonded together—electrons are involved).  Why do elements combine?  It’s about the good old “Octet Rule”  Octet Rule:8 e- in the valence quantum level is a stable amount of e-  Atoms will GAIN e- (make neg. ions) or LOSE e- (make + ions) to fulfill the octet rule & atoms can even SHARE e- to fulfill the octet rule Important terms & ideas

3. Ionic Compounds  How do elements combine? Using Ionic Bonds: electrical attraction joining 2 oppositely charged ions Ion: charged atoms (gained/lost electrons) In an ionic bond, electrons from the combining atoms are transferred (gained/lost) in a chemical reaction to achieve the octet rule. Cations and anions are made when e- transfer The oppositely charged ions attract—the electrical attraction is called an ionic bond.  Ex. K 1+ [ : O : ] 2- This process makes an Ionic Compound K 1+ Using Covalent Bonds: Elements are joined by SHARING e- to fulfill the octet rule—more on this in part 2 of this unit. Sharing e- results in a molecular compound (not an ionic compound)  Ex. C + H + H + H + H makes

4. Important Vocab. Continued:  Ionic Compound: type of compound formed when atoms gain/lose electrons (between metals/nonmetals or between 2 ions)  Formula Unit: smallest “particle” of an Ionic compound. (since ionic compounds are made of ions arranged in a repeating pattern)

5. Types of compounds All compounds Organic (carbon based compounds that are not C&O) Inorganic Compounds *binary ionic compounds with metals of variable charges (transition metol and nonmetal) Molecular (covalent) compounds 2 nonmetals Use greek prefixes in name of compound *binary ionic compounds Metal and nonmetal “Ternary’ compounds Ionic but made with polyatomic ions

6. Background on simple binary ionic compounds (metals & nonmetals of “A” groups)  Binary: only 2 elements  Ionic: made from ions (so 2 ions) that attract  form when a positive ion, (cation/metal), and a negative ion, (anion/nonmeta) attract.  The metal (cation) for these compounds forms only 1 charge.  Simple Binary ionic compounds combine elements from group 1A, 2A, 3A, (cations/metals) with elements from 5A, 6A, 7A (anions/nonmetals)  Remember, elements from the A groups are known as the Representative Elements.

8. Writing Formulas for Simple Binary (2 elements) Ionic Compounds  Determine the charges (oxidation #) on the cation and anion (charges are listed at the top of each family.  Ex. Ca +2 and Cl -1  Balance the charges (the overall charge of the compound needs to be neutral) Ex. Ca +2 Cl -1 Determine the number of each Cl -1 element needed so the charges add to zero (+2 + 2(-1)) = 0

9. Writing formulas for Simple binary ionic compounds (Type 1) cont.  Ex. Ca +2 Cl -1 Cl -1 (+2 + 2(-1)) = 0  Write the chemical formulas with subscripts to show how many of each element are needed for a net charge of zero  Ca Cl 2

10. Examples of “balancing the charges” for simple ionic compounds (charges need to add to zero)  Combine Na 1+ and S 2-  draw squares or shapes to help  Combine Mg 2+ and N 3-

11. Writing formulas for Simple binary ionic compounds cont.  Shortcut: “criss-cross” the charges to get the subscripts but be sure subscripts reduce to lowest form  Ex. Mg +2 + N -3 The formula for this compound is Mg 3 N 2  Ex. Mg +2 + O -2 Don’t need criss-cross for this! The formula for this compound is MgO (criss-cross method is not needed when charges are equal but opposite—only need one of each ion)

12. Naming simple binary ionic compounds  Write the name of the first element (the metal) in formula  Write the name of the nonmetal (anion) so that it ends in –ide  Ex. CaCl 2 = calcium chloride  Mg 3 P 2 =  NaS 2 =

13. SimpleBinary Ionic Compounds Practice Examples with Cations forming 1 Charge Write the name or formula of the given compound  1. Sodium bromide  2. NaCl  3. AlP  4. Aluminum nitride  5. Aluminum oxide  6. K 3 N  7. Barium nitride  8. Rubidium oxide  9. BaI 2 10. Magnesium phosphide

14. Simple Binary Ionic Compounds Examples with Cations forming 1 Charge  1. Sodium bromide  NaBr  2. NaCl  Sodium chloride  3. AlP  Aluminum phosphide  4. Aluminum nitride  Al N  5. Aluminum oxide  Al 2 O 3  6. K 3 N  Potassium nitride  7. Barium nitride  Ba 3 N 2  8. Rubidium oxide  Rb 2 O  9. BaI 2  Barium iodide  10. Magnesium phosphide  Mg 3 P 2

15. Binary ionic compounds with a variable charged metal (transition metal)  These are ionic compounds (Metal + Nonmetal) but… Metal is most likely a transition metal (Group B elements)—and is able to form more than 1 charge (have “variable” charges—note charges for d-block metals—almost all have more than 1 charge listed)

16. Binary ionic compounds with a transition metal (variable charge) cont.  Ex. Find Fe on the per. Table. What charges can it form ? or  Which one is present in Fe Cl 2 ??  We need to work backwards from the formula Fe ? + Cl -1 + Cl -1 …2 Cl -1 ions make a -2 charge…Fe must have a +2 charge to make this compound neutral Fe 2+ is the ion used in this compound

17. Binary ionic compounds with a transition metal (variable charge) cont.  When we write the name you must…  Name the metal first & add Roman Numerals behind the metal to show which charge was needed  Name the nonmetal (anion) with an –ide ending For FeCl 2 : Iron (II) chloride

18. Writing formulas for Binary Ionic compounds with a variably charged metal  Balance the charges just as in simple ionic compounds.  Ex.: Fe 3+ and Cl 1- 

19. Alternate (extra credit) method for naming Type II binary compounds  When a metal makes more than one cation, the cation with the highest charge is named with –ic at the end.  The cation with the lowest charge is named with an –ous ending.  Ex. Fe 3+ Iron (III) or Ferric  Ex. Fe 2+ Iron (ll) or Ferrous  FeCl 3 Iron (III) chloride or Ferric chloride  FeCl 2 Iron (II) chloride or Ferrous chloride

20. BINARY IONIC COMPOUNDS with VARIABLY CHARGED CATIONS  1. Cobalt (III) chloride  CoCl 3  2. CuCl 2  Copper (II) chloride  3. FeP  Iron (III) phosphide  4. Iron (III) sulfide  Fe 2 S 3  5. Lead (II) oxide  PbO  6. PbI 4  Lead (IV) iodide  7. Tin (IV) nitride  Sn 3 N 4  8. Mercury (II) chloride  Hg Cl 2  9. CrP 2  Chromium (II) phosphide  10. MnS 2  Manganese (II) sulfide

21. Ionic compounds with polyatomic ions General Information:  These compounds are ionic (have a cation and an anion) and attract to form an ionic bond.  They involve a different kind of ion called a polyatomic ion. (Many atoms charged)  They could have a metal for the cation and a poly atomic anion ex. MgSO 4, Na 2 SO 4  They could have a polyatomic cation and a nonmetal anion. Ex. NH 4 Cl, NH 4 F  They could have 2 polyatomic ions  Ex. NH 4 C 2 H 3 O 2, (NH 4 ) 2 SO 4

22. New Vocabulary Polyatomic ion: a group of atoms that together carry a charge. There are 9 polyatomic ions you need to know for this unit and next trimester. They are listed on back of periodic table and below: you need to memorize these.

23. Polyatomic Ions To Know 1+ 1- 2- 3- Ammonium NH 4 1+ Acetate C 2 H 3 O 2 1- Carbonate CO 3 2- Phosphate PO 4 3- Chlorate ClO 3 1- Sulfate SO 4 2- Cyanide CN 1- Hydroxide OH 1- Nitrate NO 3 1-

24. Naming ionic compounds with polyatomic ions  Identify the polyatomic ion(s) found in the formula  Name the cation first (most likely it will be a metal)  If the metal has a variable charge, determine the charge by working back (undoing) from the formula Ex. Fe 2 (SO 4 ) 3 This tells you Fe 3+ and SO 4 2- are the ions that combine in the compound The cation is named Iron (III)  Write the name of the anion (most likely it is the name of the polyatomic ion)  The anion from the example is sulfate so the full name of the compound is: Iron (III) sulfate

25. Compounds with Polyatomic Ions: Naming  1. NaNO 3 sodium nitrate  2. Na 2 SO 4 Sodium sulfate  3. MgSO 4 Magnesium sulfate  4. Mg(NO 3 ) 2 magnesium nitrate  5. NH 4 Cl  Ammonium chloride  6. (NH 4 ) 2 S Ammonium sulfide  7. NH 4 NO 3  Ammonium nitrate  8. (NH 4 ) 2 SO 4  Ammonium sulfate  9. FePO 4  Iron (III) phosphate  10. Fe 3 (PO 4 ) 2  Iron (II) phosphate  11. KMnO 4 Potassium permanganate  12. Li 2 SO 4  Lithium sulfate  13. CoPO 4  Cobalt (III) phosphate

26. Writing formulas for compounds with polyatomic ions  These compounds are ionic. You need to balance the charges just like in the other ionic compounds.  Since these will have polyatomic ions present, you will need to use ( ) around the polyatomic ion if you need more than one set of the ion.  Ex. What is the formula for Calcium nitrate? Determine the charges on the ions Ca 2+, NO 3 - Balance the charges (criss-cross method) Write the formula: Ca(NO 3 ) 2

27. Polyatomic Ions: Writing the Formulas  1. Lithium phosphate Li 3 PO 4  2. Calcium carbonate CaCO 3  3. Aluminum cyanide Al(CN) 3  4. Copper (II) hydroxide Cu(OH) 2  5. Iron (III) sulfate Fe 2 (SO 4 ) 3  6. Potassium nitrate KNO 3  7. Potassium carbonate  K 2 CO 3  8.  9. Calcium hydroxide  Ca(OH) 2  10. Ammonium nitrate  NH 4 NO 3  11. Ammonium phosphate  (NH 4 ) 3 PO 4  12. Copper (II) nitrate  Cu(NO 3 ) 2

28. Naming and formulas for any type of Ionic Compound  Na 2 O  Sodium oxide  PbO 2  Lead (IV) oxide or Lead (II) peroxide K2SK2S  Potassium sulfide  LiNO 3  Lithium nitrate  Fe 2 (CO 3 ) 3  Iron (III) carbonate Copper (II) bromide CuBr 2 Zinc oxide ZnO Magnesium chloride MgCl 2 Copper (II) phosphate Cu 3 (PO 4 ) 2 Iron (II) hydroxide: Fe(OH) 3

29. More terms:  Molecular Compound: compound formed when atoms share electrons (between 2 non metals)  Molecule: structure formed when 2 or more atoms (nonmetals) share e- to complete the octet rule (8 e-)  Covalent bond: chemical bond formed by sharing e-  Single:  Double:  Triple:  Can show with Lewis Dot Structures ex.

30. Molecular compounds—Covalent Bonds

31. Naming Molecular Binary Compounds  These compounds have 2 nonmetals in them. They are combined by sharing electrons. So, these are covalent/molecular compounds  Review: Where are nonmetals found on the periodic table?  What are their electron dot (Lewis dot) structures?  Rules for naming molecular (covalent) compounds  First element in formula is named by its full name  Second element in formula is named with –ide ending  Prefixes are used to denote the #’s of atoms present for each element The prefix mono is never used for naming the first element. Ex. CO is carbon monoxide, not monocarbon monoxide!

32. Greek Prefixes—memorize these! Mono Di Tri Tetra Penta Hexa 123456123456 PrefixNumber indicated

33. More prefixes  Hepta  Octa  Non  deca  7  8  9  10 PrefixNumber indicated

34. Examples  BF 3  NO N2O5N2O5  Boron Trifluoride  Nitrogen monoxide  Dinitrogen pentoxide  What do you notice on the ending? FormulasNames

35. Naming and Writing Formulas for Binary Molecular Compounds  1. Boron trifluoride BF 3  2. B 6 O Hexaboron monoxide  3. N 4 S 8 Tetranitrogen octasulfide  4. Carbon dioxide CO 2  5. NH 3 Nitrogen trihydride  6. As 2 O Diarsenic monoxide  7. Iodine heptachloride I Cl 7  8. BI 6 Boron hexaiodide  9. B 5 H 9 Pentaboron nonahydride  10. Dinitrogen monoxide N 2 O  11. P 4 O 10 Tetraphosphorus decoxide  12. Sulfur dichloride S Cl 2

36. Naming and formula writing for any type of compound  1. KOH  2. Na 2 CO 3  3. Cobalt (III) nitrate  4. CaCl 2  5. N 2 O 4  6. FeBr 3  7. Phosphorus triiodide  8. Fe(NO 3 ) 3  9. Ammonium cyanide  10. Magnesium chloride  11. Barium acetate  12. P 2 O 6

37. Answers to compound names/formulas  1. KOH  Potassium hydroxide  2. Na 2 CO 3  Sodium carbonate  3. Cobalt (III) nitrate  Co (NO 3 ) 3  4. CaCl 2  Calcium chloride  5. N 2 O 4  Dinitrogen tetroxide  6. FeBr 3  Iron (III) bromide  7. Phosphorus triiodide PI 3  8. Fe(NO 3 ) 3  Iron (III) nitrate  9. Ammonium cyanide  NH 4 CN  10. Magnesium chloride  MgCl 2  11. Barium acetate  Ba(C 2 H 3 O 2 ) 2  12. P 2 O 6  Diphosphorus hexoxide

38. Questions to Ask Yourself When Naming or writing formulas for Compounds  Is the Compound Binary (only two elements)?  Is the compound Molecular or Ionic (is there a metal present?  If Ionic, does the Cation require use of Roman Numerals (can the metal have more than one charge)?  If ionic, is there a polyatomic ion present?

39. Is the Compound Binary? Follow rules for Naming Binary Type III and Use Prefixes Follow Rules for Naming with Polyatomics Is the Compound Molecular or Ionic (molecular is 2 nonmetals, ionic is metal and nonmetal)? Does the Cation form more than 1 charge? Follow Rules for Naming Binary Type I Compounds with “Single Charged” Cations Follow Rules for Naming Binary Type II with “Variably Charged” Cations and Use Roman Numerals YES NO IONIC MOLECULAR NOYES HINT: Don’t forget to check for variably charged cations when naming with polyatomic ANIONS!!!