3.2 Names and Formulas of Ionic Compounds Objectives By the end of the lesson you should be able to: Describe simple and complex ions Name and make all types of ionic compounds WARM UP! Counting Atoms Practice Formula
# of Atoms Formula 1) NaCl 4) Mg(OH)2 2) HNO3 5) (NH4)2O 3) H2SO4
6) NH4NO3 # of Atoms Complex and Simple Ions Simple H+ Ions: one atom with a charge S-2 Cu+1
Cu+2 Complex Ions: more than one atom with an overall charge Called polyatomic ions Listed on pg 92 in your textbook SO4-2 NO3-1 NH4+1 Remember
ALL ELEMENTS WANT TO HAVE FULL OUTER SHELLS! The combining capacity (AKA: charge) tells you how many electrons have been lost/gained to get a full outer shell Names and Formulas Naming compounds: involves writing out the entire name for each element in the compound
Compound and symbols given make name! Formulas: involve using symbols of each element to make the compound Name given make compound with symbols Ionic Compounds
Always involve a positive charge (metal) and a negative charge (non-metal) Electrons are always transferred from the positive to the negative Create ions because losing and gaining electrons (charges result) Naming Ionic Compounds Metal always first; name never changes Non-metal second; ending becomes ide
EX: NaCl = sodium chloride MgF2 = magnesium fluoride Al2O3 = aluminum oxide Your Turn! Practice Problems pg. 86 (check your answers on page 509!) Chemical Formulas of Ionic Compounds Formulas
contain symbols to identify each ion in an ionic compound, as well as the relative numbers of ions in the compound. Example: NaCl 1 sodium:1chlorine CaF2 1 calcium:2 fluorines Note: Relative numbers of each ion is a subscript to the right of the symbol Ionic Compound Formulas 1. Get symbol and charge
2. Charges are the same skip to step 2 If charges are different swap and drop Combine Example of a Metal & Nonmetal Combining Calcium chloride 2. Ca Cl 3. Ca 2+ Cl 14. Ca 2+ Cl 15. CaCl2
1. (write the symbols) (superscript combining capacities) (drop the +/- signs and cross combining capacities) Your Turn! Practice Problems pg. 87 (check your answers on page 509!) Multivalent Ionic Compounds
Multivalent = more than one combining capacity Found in the Transition Metals section Same naming as Ionic Compounds BUT use a roman numeral to show which combining capacity is used I 1 II 2
III IV V 3 4 VI 5 VII 6 VII 7 8
Multivalent Ionic Compound Formulas (Roman Numeral given) 1. 2. Get symbol and possible charges Choose appropriate ion (from Roman Numeral) 3. Charges are the same skip to step 2 If charges are different swap and drop
Combine Your Turn! Practice Problems pg. 89 (check your answers on page 509!) Compounds Containing Multivalent Metals Notice that some metallic elements have more than 1 ion charge.
We need to use Roman Numerals to indicate which combining capacity is used. E.g. Copper (II) chloride = Cu +2 E.g. Copper (I) chloride = Cu +1 Naming Note: Multivalent Metal Use the Roman Numeral equal to the ionic charge to indicate which combining capacity was used E.g. CuCl2 Cu1+ or Cu2+ ? You need to reverse Copper (II) chloride
cross to find combining E.g. Fe2O3 capacities. Fe3+ or Fe2+ ? Iron (III) oxide Naming Multivalent Ionic Compounds (no Roman Numeral given) 1. 2. 3. 4. Get possible charges
Determine which charge will give the correct formula (reverse swap and drop) Write the name same as you did with Ionic Compounds Add the appropriate Roman Numeral between the metal and non-metal Your Turn! Practice Problems pg. 90 (check your answers on page 509!) Naming Polyatomic Ionic Compounds
1. 2. 3. Usually seen in more complicated compounds List of Polyatomic Ions is found in your textbook on pg.92 and on the back of your PT Look up both names Check for multivalent charges and insert Roman Numerals if need be
Combine Reactions involving Polyatomic Ions (Radicals) E.g. Ammonium sulfide Ammonium = NH 1+ (1+ is the ion charge) 4 (given on the back of the Periodic Table) When NH4 1+ and S-2 combine, the NH4 polyatomic ion group stays together You need to put brackets around NH4 so you
can separate the digits then swap and drop. So, (NH ) 1+ S 24 (NH4)2 S Polyatomic Ionic Compound Formulas 1. Get symbol and possible charges 2.
If same skip to step 2 If different swap and drop Combine use brackets if need be for polyatomic ions ONLY Radicals & Roman Numerals Copper sulfate Copper (II) sulfate 1. Cu SO4 2. Cu
2+ SO4 2- 3. Cu 2+ SO4 2- 4.Cu2(SO4)2 5.Cu(SO4) the 2s reduce
brackets can be dropped Your Turn! Practice Problems pg. 91 (check answers on page 509!) Worktime! Workbook p. 46 49 Textbook p. 95 for extra practice if you need!
