Polyatomic Ionic Compounds Definition Polyatomic Ion more than

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Polyatomic Ionic Compounds

Polyatomic Ionic Compounds

Definition Polyatomic Ion- more than one atom that together have a charge Polyatomic Ionic

Definition Polyatomic Ion- more than one atom that together have a charge Polyatomic Ionic Compoundcompound containing at least one polyatomic ion + Cation Polyatomic Anion Polyatomic Ionic Compound

Common Polyatomics Name Symbol OH-1 Hydroxide NO 3 -1 Nitrate Cl. O 3 -1

Common Polyatomics Name Symbol OH-1 Hydroxide NO 3 -1 Nitrate Cl. O 3 -1 Chlorate CO 3 -2 Carbonate SO 4 -2 Sulfate PO 4 -3 Phosphate NO 2 -1 Nitrite SO 3 -1 Sulfite CN-1 Cyanide HCO 3 -1 Bicarbonate C 2 H 3 O 2 -1 Acetate Cl. O 4 -1 Perchlorate Cl. O 2 -1 Chlorite Cl. O-1 Hypochlorite NH 4+1 Ammonium

Practice Identifying Polyatomic Ions Example: Identify and name the polyatomic ion in each compound

Practice Identifying Polyatomic Ions Example: Identify and name the polyatomic ion in each compound Na. NO 3 NH 4 Cl Ca(OH)2 (NH 4)3 PO 4 K 2 CO 3 Note: Parenthesis are only used on POLY’s and only when we need more than one. You can’t change the subscript on the poly. Example - Al 2(SO 4)3 Three SO 4 -2 groups NOT SO 43 -2

Practice Identifying Polyatomic Ions Example: Identify and name the polyatomic ion in each compound

Practice Identifying Polyatomic Ions Example: Identify and name the polyatomic ion in each compound Na. NO 3 Nitrate NH 4 Cl Ammonium Ca(OH)2 Hydroxide (NH 4)3 PO 4 Ammonium & phosphate K 2 CO 3 Carbonate

Naming Polyatomic Ionic Compounds l To name these compounds: ¡ Write the name of

Naming Polyatomic Ionic Compounds l To name these compounds: ¡ Write the name of the cation ¡ If it is a metal just name the metal ¡ If it is a multivalent metal, name the metal and put a set of parenthesis after it ¡ If it is a NH 4 write down the name ammonium ¡ Name the anion ¡ If the anion is a polyatomic ion, just name the polyatomic ¡ If the anion is a single non-metal element, write its name with the suffix “-ide” ¡ Determine the roman numeral if it is multivalent

Example #1 Na. NO 3

Example #1 Na. NO 3

Example #1 “Sodium” Cation Na. NO 3 Polyatomic Anion “Nitrate” Sodium Nitrate

Example #1 “Sodium” Cation Na. NO 3 Polyatomic Anion “Nitrate” Sodium Nitrate

Example #2 K 2 SO 4

Example #2 K 2 SO 4

Example #2 “Potassium” Cation K 2 SO 4 Polyatomic Anion “sulfate” Potassium sulfate

Example #2 “Potassium” Cation K 2 SO 4 Polyatomic Anion “sulfate” Potassium sulfate

Example #3 Cu(OH)2

Example #3 Cu(OH)2

Example #3 “Copper” A Multivalent Metal Cation Cu(OH)2 Two OH-1 groups provide a total

Example #3 “Copper” A Multivalent Metal Cation Cu(OH)2 Two OH-1 groups provide a total charge of -2. The Copper has to be +2 to balance this charge. Polyatomic Anion “hydroxide” Copper (II) hydroxide

Example #4 (NH 4)2 S

Example #4 (NH 4)2 S

Example #4 “Ammonium” Polyatomic Cation (NH 4)2 S Anion “sulfur” becomes “sulfide” Ammonium sulfide

Example #4 “Ammonium” Polyatomic Cation (NH 4)2 S Anion “sulfur” becomes “sulfide” Ammonium sulfide

Writing Formulas for Polyatomic Ionic Get out your Poly List!!!! l To write these

Writing Formulas for Polyatomic Ionic Get out your Poly List!!!! l To write these formulas: ¡ Write the symbol & charge of the cation & anion ¡ Add additional cations or anions to have a neutral compound. (We once again do this by balancing charge. Methods such as the Swap/Drop/Reduce or Lowest Common Multiple) ¡ Use subscripts to show the number of ions l When using subscripts with a polyatomic ion, you must put the polyatomic ion in parenthesis.

Example #1 Sodium carbonate

Example #1 Sodium carbonate

Example #1 Na+1 Cation Sodium carbonate Polyatomic Anion CO 3 -2

Example #1 Na+1 Cation Sodium carbonate Polyatomic Anion CO 3 -2

Example #1 Na+1 Cation Na+1 CO 32 - Sodium carbonate Polyatomic Anion CO 3

Example #1 Na+1 Cation Na+1 CO 32 - Sodium carbonate Polyatomic Anion CO 3 -2 Na 2 CO 3 +1 + -2 = -1 Na+1 CO 32+1 + -2 = 0 The subscript “ 2” is used to show that 2 cations are needed.

Example #2 Magnesium nitrate

Example #2 Magnesium nitrate

Example #2 Mg+2 Cation Magnesium nitrate Polyatomic Anion NO 3 -1

Example #2 Mg+2 Cation Magnesium nitrate Polyatomic Anion NO 3 -1

Example #2 Mg+2 NO 3 - Cation +2 + -1 =+ 1 Magnesium nitrate

Example #2 Mg+2 NO 3 - Cation +2 + -1 =+ 1 Magnesium nitrate Mg+2 NO 3 - Polyatomic Anion +2 + -1 = 0 NO 3 -1 Mg(NO 3)2 The subscript “ 2” is used to show that 2 anions are needed. Use parenthesis when adding subscripts to polyatomic ions