Nomenclature Ternary Ionic Compound and Acids

Rules for Writing Formulas for Ternary Ionic Compounds – these are compounds containing polyatomic ions. Rules for Writing Formulas for Ternary Ionic Compounds – these are compounds containing polyatomic ions. Polyatomic Ions-two or more elements (usually nonmetals) bonded together that have collectively lost or gained electrons and now have a charge.

1. Write the cation first and the anion second. 2. Determine oxidation numbers (they are given to you for polyatomic ion) 3. Crisscorss the oxidation numbers 4. If a subscript must be added to a polyatomic ion, keep the polyatomic ion in parentheses. Example: Ammonium sulfide (NH 4 ) 1+ S 2- (NH 4 ) 2 S

Practice: aluminum sulfate _______________ potassium chlorate ______________ Iron (III) oxalate _______________________ magnesium chlorate _____________________ Magnesium dichromate __________________ tin (II) hypochlorite ____________________ Lead (II) perchlorate__________________ Ammonium carbonate___________________ Hint: polyatomic ions will usually end in –ate or –ite, while singular ions will end in ide Ex: sulfate is SO 4 -2 and sulfide is S -2 (Exceptions are cyanide, hydroxide, and ammonium)

Rules for Writing Names for Ternary Ionic Compounds - these are the compound containing polyatomic ions. Rules for Writing Names for Ternary Ionic Compounds - these are the compound containing polyatomic ions. 1. The correct full name of the cation (metal ion or polyatomic ion) is written first. (Do not forget about the roman numerals if it is a tansition metal, Sn, or Pb ion!) 2. The correct full name of the anion (polyatomic ion or nonmetal ion) is written second. If the anion is a polyatomic ion do not change the ending. If the anion is a nonmetal ion then the ending is dropped and –ide is added. Example: KNO 3 potassium nitrate Example: Cu 2 CrO 4 copper (I) chromate

Practice: Al 2 (SO 4 ) 3 _________________________________ PbCO 3 __________________________________ Li 2 SO 3 ________________________ CaCr _______________________________ NH 4 Cl_________________________ CsClO 4 __________________________________ K 2 CN ________________________

Writing Names and Formulas for Acids Writing Names and Formulas for Acids Rules for Writing Names for Acids Acids: Any compound starting with hydrogen is an acid. Acids: Any compound starting with hydrogen is an acid. Even though acids usually contain only nonmetals, they are treated as ionic compounds because the hydrogen present is the H +1 ion. Even though acids usually contain only nonmetals, they are treated as ionic compounds because the hydrogen present is the H +1 ion.

Rules for writing the name of an acid: Does the compound contain an oxygen atom? If No – always start with hydro, then the root of the second element, and end with -ic. Example: HClhydrochloric acid If Yes – oxygen is present – start with the root of the anion (usually a polyatomic ion). If it ends in –ate, change it to –ic. If the anion ends in –ite, change it to –ous. Example: HNO 3 Nitric acid

Examples of Polyatomic Ions in Acids: Acetate - acetic Chlorate - chloric Nitrite - nitrous Sulfite - sulfurous Phosphate - phosphoric Perchlorate - perchloric Hypochlorite - hypochlorous Carbonate - carbonic

Practice: HNO 2 HClH 2 SO 4 HBrH 3 N HF HIH 2 S

Rules for Writing the Formula for an Acid: Rules for Writing the Formula for an Acid: 1. Hydrogen will always be the cation (H +1 ). 2. Determine oxidation numbers (they are given to you for polyatomic ion) 3. Crisscorss the oxidation numbers 4. If a subscript must be added to a polyatomic ion, keep the polyatomic ion in parentheses. Example: phosphoric acid H 1+ (PO 4 ) 3- H 3 PO 4

nitric acid_________________ acetic acid______________________ chloric acid ___________________ chlorous acid__________________ Hydrosulfic acid _____________

Let’s Review: Binary Molecular Compounds (BMC): 2 elements, both are nonmetals, will use prefixes, will in with -ide Binary Ionic Compounds (BIC): 2 elements, one is a metal and one a nonmetal, will end with –ide, use periodic table to look up oxidation to determine the formula, transition metal, lead, and tin ions get roman numerals

Ternary Ionic Compounds (TIC): 3 or more elements, at least one is a metal and at least one is a nonmetal, these will contain a polyatomic ion use the oxidation numbers to determine the formula Acids (A): will begin with H, hydrogen’s charge when forming an acid is H +1, If the acid does NOT contain oxygen then start the name with hydro-, followed by the root of the second element, and end with –ic. If the acid does contain oxygen start with the root of the anion (usually a polyatomic ion) and then change the ending to –ic if it was –ate and –ous if it was –ite.

Quiz: Nomenclature 1.CaCO 3 4.Mg 3 P 2 2.O 3 N 10 5.HCl 3.CuCl 2 6.Carbon tetrachloride 7.Barium fluoride 8.Iron (III) nitrate 9.Sulfuric acid 10.Lead (IV) oxide