Chapter 9: Chemical Names and Formulas Naming and Writing Formulas for Ionic Compounds

Learning Targets You will learn to name and write ionic compounds. (**different than LT sheet**) You will learn the names for common polyatomic ions and how to use them in naming and writing compounds.

You will learn to name and write ionic compounds. Nomenclature We are learning how to name and write chemical compounds and formulas. Remember rules for writing formulas: Compounds contain the types of atoms (element symbols) and the number of each type of atom in a formula The number of each atom is indicated by a subscript written to the right of the element symbol (with the exception of 1) You will learn to name and write ionic compounds. You will learn the names for common polyatomic ions and how to use them in naming and writing compounds.

You will learn to name and write ionic compounds. Nomenclature Binary ionic compound – metal and nonmetal bonded together Metals have a positive charge (cation) and non-metals have a negative charge (anion). Metals can be Type I or Type II cations Type I – only one charge (groups 1, 2, and 3) Type II – more than one charge (NOT groups 1-3, denoted by a roman numeral) *we will not test over Type II You will learn to name and write ionic compounds. You will learn the names for common polyatomic ions and how to use them in naming and writing compounds.

Polyatomic Ions Polyatomic Ions - charged particles composed of several atoms bonded together. Polyatomic ions containing oxygen are called oxyanions. There are several series of polyatomic ions where there are different numbers of oxygen atoms. You will learn the names for common polyatomic ions and how to use them in naming and writing compounds.

Compounds with polyatomic ions Compounds with polyatomic ions are NOT binary (this should be your hint!) We needed to memorize polyatomic ions because we cannot get their names or formulas from the periodic table! Remember polyatomic ions are a group of many atoms and CANNOT be broken up. You will learn the names for common polyatomic ions and how to use them in naming and writing compounds.

Rules for writing formulas for Ionic compounds Write the symbols Assign the charges -KNOW YOUR ION CHARGES -Roman numeral = charge on cation Sum the charges to zero (a MUST for ionic compounds). IF a subscript is needed for the polyatomic ion, put the polyatomic ion in PARENTHESES with the subscript outside of it. We’ve been over these charges before! You will learn to name and write ionic compounds. You will learn the names for common polyatomic ions and how to use them in naming and writing compounds.

Rules for naming Ionic compounds The cation is named first and comes from its element or polyatomic ion name. If your cation is type II, use a roman numeral after it to indicate the charge. The anion is named second and is named by taking the root of its element name and adding –ide or from the polyatomic ion name . Common Anions: Hydrogen - hydride Fluorine - fluoride Chlorine - chloride Bromine - bromide Iodine - iodide Oxygen - oxide Sulfur - sulfide You will learn to name and write ionic compounds. You will learn the names for common polyatomic ions and how to use them in naming and writing compounds.

Examples Name or write the formula for each ionic compound: CsF AlCl3 Magnesium iodide Sodium chloride Na2SO4 KH2PO4 Calcium hydroxide Sodium phosphate Answers: Cesium fluoride Aluminum chloride Magnesium iodide NaCl Sodium sulfate Potassium dihydrogen phosphate Ca(OH)2 Na3PO4 You will learn to name and write ionic compounds. You will learn the names for common polyatomic ions and how to use them in naming and writing compounds.

Try on your own Rubidium oxide Strontium iodide K2S MgBr2 NaCN Name or write the formula for each ionic compound: Rb2O SrI2 Potassium sulfide Magnesium bromide Sodium cyanide Calcium hydrogen carbonate KHSO4 NH4I Potassium permanganate Answers: Rubidium oxide Strontium iodide K2S MgBr2 NaCN Ca(HCO3)2 Potassium hydrogen sulfate Ammonium iodide KMnO4 You will learn to name and write ionic compounds. You will learn the names for common polyatomic ions and how to use them in naming and writing compounds.

Type II Examples (not on test) Name or write the formula for each ionic compound: CuCl Fe2O3 Lead (IV) chloride Tin (IV) oxide PbBr2 FeS PbCO3 Iron (II) hydroxide Answers: Copper (I) chloride Iron (III) oxide PbCl4 SnO2 Lead (II) bromide Iron (II) sulfide Lead (II) carbonate Fe(OH)2 You will learn to name and write ionic compounds. You will learn the names for common polyatomic ions and how to use them in naming and writing compounds.

Type II Try on your own (not on test) Name or write the formula for each ionic compound: Cobalt (III) chloride Mercury (II) oxide Fe(NO3)3 Mn(OH)2 Cobalt (II) perchlorate Copper (II) nitrite Cu(NO3)2 Answers: CoCl3 HgO Iron (III) nitrate Manganese (II) hydroxide Co(ClO4)2 Cu(NO2)2 Copper (II) nitrate You will learn to name and write ionic compounds. You will learn the names for common polyatomic ions and how to use them in naming and writing compounds.