4.2 Names and Formulas of Compounds Ionic ________________________are made up of _______________ and _____________ ions. All of the positive and negative ions organize in a _________________. Negative-positive _______________. Negative-negative and positive-positive _________. Ionic compounds form from the inside out as ___________________________. A salt shaker contains thousands of small pieces of NaCl (each tiny grain of salt you see is made of many Na and Cl ions, NOT just one of each) Salt, NaCl See pages 184 - 185 Water, H2O (c) McGraw Hill Ryerson 2007

Names and Formulas of Compounds Covalent _____________________share electrons. There is generally no order to the formation of covalent molecules. These molecules ____________________________as solids, liquids or gases. Covalent molecules are like a play-pit full of plastic balls. Each plastic ball = 1 _______________________of H2O (c) McGraw Hill Ryerson 2007

The Chemical Name and Formula of an Ionic Compound The _______________ of an ionic compound = positive ion + negative ion-ide. We can write the name if we know the two elements involved: For example, an ________________________________forms between magnesium and oxygen. The_____________________is the first part of the name, ______________________. The __________________________forms part of the ending of the name, __________________. Add -ide to the end of the name to form _________________________________. Magnesium oxide is used as a drying agent. (c) McGraw Hill Ryerson 2007

The Chemical Name and Formula of an Ionic Compound We can also make a name from an ________________________________________ For example, what is the name of Ca3N2? Ca, the __________________ ion, is ___________________. N, the __________________ ion, is ____________________. Drop the end of the anion and add ____________ ____________________________ See pages 186 - 187 (c) McGraw Hill Ryerson 2007

Naming Ionic Compound Examples Name the following: 1. NaBr 2. MgS 3. AlF3 4. Fe2O3 (c) McGraw Hill Ryerson 2007

The Chemical Name and Formula of an Ionic Compound (continued) Writing ___________________ for ionic compounds: In an ionic compound, the ____________________charges balance out the ______________________ charges. To do this, we need to criss-cross the charges (see below) The ratio is always written in the lowest possible form. For example, what is the formula for magnesium phosphide? Calcium oxide, also known as “quicklime” was once produced by cooking limestone in ancient kilns. magnesium is ________ phosphorous is __________ Criss-cross to get: See page 188 (c) McGraw Hill Ryerson 2007

Ionic Formula Examples Write the formulas for the following compounds: 1. Magnesium Phosphide 2. Calcium Bromide 3. Aluminum Oxide 4. Lithium Nitride (c) McGraw Hill Ryerson 2007

Formula of an Ionic Compound with a Multivalent Metal Some transitional metals are _____________________meaning they have ___________________________ion form. On the periodic table, the most common form of the ion is listed __________ In the name of the compound, ___________________________are used following the positive ion to indicate ________________________was used. For example, what is the formula manganese (III) sulphide? This manganese is ___________, sulfur is _________ ____________________ For example, what is the name of TiF4 titanium is ____________ Roman numeral: __________ ____________________________ See pages 189 - 191 (c) McGraw Hill Ryerson 2007

Polyatomic Ions Some ions, called _________________________, are made up of ____________________joined together with covalent bonds. The __________________________has a + or – charge, not the individual atoms. When naming these compounds, DO NOT change the ending of the polyatomic ion! See pages 192 - 193 (c) McGraw Hill Ryerson 2007

Polyatomic Examples Write the formula for the following: 1. Sodium sulphate 2. Potassium permanganate Write the name for the following: 1. KClO 2. Fe(OH)3 (c) McGraw Hill Ryerson 2007

Names and Formulas of Covalent Compounds Covalent compounds are also called__________________. Covalent compounds are made up of two or more ____________. Subscripts mean something different in covalent compounds Ionic compounds subscripts show the smallest whole-number _________________between the ions in the compound. Covalent molecules have subscripts that show the _____________________________ of atoms in the molecule. See page 193 (c) McGraw Hill Ryerson 2007

Naming Covalent Compounds Covalent compounds (two non-metal atoms) use a system of _____________ for naming. Prefixes (mono, di, tri, etc) are often used _________________ the atom name to indicate the number of atoms in the molecule. You must always use prefixes EXCEPT for the first atom when there is only one of them, then you may leave out the ‘mono’ CO2 = carbon dioxide, not monocarbon dioxide Write the most ___________________ atom (farthest left) first Add -ide to the end of the second atom’s name See pages 194 - 195 (c) McGraw Hill Ryerson 2007

Covalent Compounds Examples Write names for the following compounds: 1. Si3P6 2. N2O4 3. NI3 (c) McGraw Hill Ryerson 2007

Covalent Compound Examples Write formulas for the following compounds: 1. Trinitrogen tetrachloride Dichlorine monoxide Carbon tetraiodide (c) McGraw Hill Ryerson 2007

Comparing Ionic and Covalent Compounds To determine whether a compound is ionic or covalent: Examine the formula. Ionic compounds start with a metal or the ammonium ion. Covalent compounds start with a non-metal. If the compound is covalent: Use the prefix system of naming if the compound does not start with hydrogen. (If it does, then it is an acid. We will learn about those soon.) If the compound is ionic: Check the metal to see if it is multivalent (add a Roman numeral if it is multivalent). Naming starts with the name of the metal atom. If it ends with a single non-metal, naming will just end in -ide. If it ends in a polyatomic ion, look up the name/formula in the chart See pages 196 - 197 (c) McGraw Hill Ryerson 2007