Polyatomic IonsPolyatomic Ions  An ion that is a collection of multiple atoms  The atoms of the ion are covalently bonded  The entire group of atoms has an overall charge

Polyatomic IonsPolyatomic Ions  To write the formula of an ionic compound, treat the polyatomic ion the same as a single element ion  To show multiples of a polyatomic ion in a formula, place the entire polyatomic ion inside parentheses with a subscript outside for the number present  Ex. Mg(NO 3 ) 2  NEVER change the subscripts of the polyatomic ion

Polyatomic IonPolyatomic Ion  When naming follow the same rules where cation is in front of the anion  Unlike monatomic ions, you DO NOT change the name  Ex. Ca 2+ & CO 3 2- = CaCO 3  Calcium ion & Carbonate = Calcium Carbonate

Polyatomic Ion PracticePolyatomic Ion Practice  Barium and Nitrate Ba 2+ NO 3 1- Ba(NO 3 ) 2

Polyatomic Ion PracticePolyatomic Ion Practice  Barium and Nitrate Ba 2+ NO 3 1- Ba(NO 3 ) 2  Ammonium and Sulfite NH 4 1+ SO 3 2- (NH 4 ) 2 SO 3

Polyatomic Ion PracticePolyatomic Ion Practice  Barium and Nitrate Ba 2+ NO 3 1- Ba(NO 3 ) 2  Ammonium and Sulfite NH 4 1+ SO 3 2- (NH 4 ) 2 SO 3  Ammonium and Phosphate NH 4 ? PO 4 ? (NH 4 ) ? PO 4?

Polyatomic Ion PracticePolyatomic Ion Practice  Barium and Nitrate Ba 2+ NO 3 1- Ba(NO 3 ) 2  Ammonium and Sulfite NH 4 1+ SO 3 2- (NH 4 ) 2 SO 3  Ammonium and Phosphate NH 4 ? PO 4 ? (NH 4 ) ? PO 4?  Potassium and Dichromate K ? Cr 2 O 7 ? K ? Cr 2 O 7?

Polyatomic Ion PracticePolyatomic Ion Practice  Calcium and Hydrogen Phosphate  Sodium and Sulfate  Magnesium and Hydroxide  Ammonium and Cyanide

Elements with Multiple Charges  Not all elements have only one charge that they can have  In fact, some elements have as many as three or four different possible charges  NOTE: All elements with multiple charges are metals, therefore they will always be the cation of the ionic compound.

Elements with Multiple Charges  Elements that have multiple charges are:  Transition Metals  Rare Earth Metals  The metals at the bottom of Groups 3A-5A (or 13-15)

Elements with Multiple Charges  Copy Table 5.4 on p. 164 into your notes  These are some of the most common examples of elements with multiple charges  Pay attention to the charge of the ion and the roman numeral in the name

Elements with Multiple Charges  Naming Rules are the same again with the addition of the number on metal  Unlike ions with a constant charge, you must add the roman numeral for the charge of the metal  Ex. Fe 2+ & SO 4 2- = FeSO 4  Iron(II) ion & Sulfate = Iron(II) Sulfate

Multiple Charges PracticeMultiple Charges Practice  Chromium (III) and Nitrate Cr 3+ NO 3 1- Cr(NO 3 ) 3

Multiple Charges PracticeMultiple Charges Practice  Chromium (III) and Nitrate Cr 3+ NO 3 1- Cr(NO 3 ) 3  Copper (II) and Sulfite Cu 2+ SO 3 2- CuSO 3

Multiple Charges PracticeMultiple Charges Practice  Chromium (III) and Nitrate Cr 3+ NO 3 1- Cr(NO 3 ) 3  Copper (II) and Sulfite Cu 2+ SO 3 2- CuSO 3  Gold (III) and Phosphate Au ? PO 4 ? Au ? PO 4?

Multiple Charges PracticeMultiple Charges Practice  Chromium (III) and Nitrate Cr 3+ NO 3 1- Cr(NO 3 ) 3  Copper (II) and Sulfite Cu 2+ SO 3 2- CuSO 3  Gold (III) and Phosphate Au ? PO 4 ? Au ? PO 4?  Manganese (VII) and Dichromate Mn ? Cr 2 O 7 ? Mn ? (Cr 2 O 7 ) ?

Multiple Charges PracticeMultiple Charges Practice  Copper (I) and Sulfite  Tin (IV) and Fluoride  Lead (II) and Sulfide  Nickel (III) and Acetate  Manganese (III) and Hydroxide