January 15, 2014 Brain Bender What does the prefix “poly” mean? Considering that, what do you think a polyatomic ion is?

Naming Ionic Compounds with Polyatomic Ions Complex Ionic Compounds

Polyatomic Ions: “Poly” – many/multiple/more than one Polyatomic ions – ions that are made up with more than one atom Examples: NO3-1 SO4-2 MnO4-1 C2H3O2-1 _These are compounds that act just like an individual element

Complex Ionic Compounds Any ionic compound that contains three or more elements. It can ONLY occur if there is a polyatomic ion present in the compound.

This is your list, please do not lose it

Let’s Practice: Identify the compounds with polyatomic ions: Hint: Look for 3 or more different atoms in the compound. NaCl Co(CO3)2 Li2SO4 CsNO3 MgO Cr3(PO4)2

Rules for naming Complex Ionic Compounds: Name the first element directly off the periodic table, IF IT IS A METAL *Remember to identify the charge of any transition metal using roman numerals Name the second element, IF IT IS A NONMETAL, by changing the ending to -ide If either of the elements is a polyatomic, name it directly off the polyatomic list, replacing step 1 or 2. Na2CO3 Sodium Carbonate

Naming Complex Ionic Compounds: Name the first element directly off the periodic table, IF IT IS A METAL *Remember to identify the charge of any transition metal using roman numerals Name the second element, IF IT IS A NONMETAL, by changing the ending to -ide If either of the elements is a polyatomic, name it directly off the polyatomic list, replacing step 1 or 2. NH4Cl Ammonium Chloride

Naming Complex Ionic Compounds: When we need multiple polyatomic ions to create a neutral compound, ( ) are used around the polyatomic ion. The subscript is placed OUTSIDE of the ( ) The polyatomic ion MUST be treated as ONE atom….it is a unit that CANNOT be separated. Ca+2 ClO3-1 Ca(ClO3)2 Calcium Chlorate

Nonmetal (or polyatomic) Let’s Practice: Compound Metal (or polyatomic) Nonmetal (or polyatomic) Compound Name: NH4ClO3 Fe(NO3)2 Mg3(PO4)2 (NH4)2O Mn(C2H3O2)3 Al(OH)3

Rules for writing compound formulas: Write out the ions for each of the elements/polyatomic present Write the charge with each ion present Drop the signs (+/-) Swap the numbers Simplify if necessary Sodium Phosphate Na+1 PO4-3 Na3PO4

Here’s another example: Write out the ions for each of the elements/polyatomic present Write the charge with each ion present Drop the signs (+/-) Swap the numbers Simplify if necessary Aluminum Carbonate Al+3 CO3-2 Al2(CO3)3

Let’s Practice: Compound Name Metal (or polyatomic) symbol and charge Nonmetal (or polyatomic) symbol and charge Compound Beryllium Nitrate Chromium (II) Hydroxide Gallium Chlorate Ammonium Carbonate Zirconium (III) Sulfate