Chemical Formulas and Naming Chemical Compounds (SCH3U)

SCH3U CHEMICAL FORMULAS AND NAMING CHEMICAL COMPOUNDS Section 2.4 CHEMICAL FORMULAS: * What’s the formula for water? * What’s the formula for met...

SCH3U CHEMICAL FORMULAS AND NAMING CHEMICAL COMPOUNDS Section 2.4 CHEMICAL FORMULAS: * What’s the formula for water? * What’s the formula for methane? * What’s the formula for glucose? * What’s the formula for baking soda? Chemical formulas provide important pieces of information: o The that make up the o The of each element that are present in the compound The of the elements in a formula also gives important information: o The electronegative element usually comes o More electronegative elements follow CaBr2 * What information does that formula give you? * Molecule contains and * Molecule has atom of Ca and atoms of Br * is the less electronegative element Lewis Diagram: Chemical Formula: COVALENT: * Formulas represent how many of are in each molecule * NH3 = nitrogen, hydrogen  1 SCH3U IONIC: * Formulas represent the in which are present in the formula * MgO = a ratio of Mg to O in the compound BONDING CAPACITY: * Every element has a certain capacity to combine with other atoms * A is assigned to each element to describe the element’s bonding capacity * This number is called the * It can also be called the and is the same as the charge on the atom when it forms an ion As a general rule: If the compound is , the valence tells you the on the formed If the compound is , the valence tells you how many the atoms contribute to the VALENCE NUMBERS: * The on the periodic table can be used to predict valence numbers Valence TRANSITION VALENCE NUMBERS: * Many of the transition metals have valence number because the in these elements is much more complex * Remember electron orbitals? s, p, d, f? They hybridize. Want to learn more? Take grade 12… POLYATOMIC IONS: * Compounds that contain made from are called ions * PO43-, are polyatomic ions * Polyatomic ions are , but it is the OVERALL that is charged, not each individual 2  SCH3U NOMENCLATURE: * In the past, there have been different ways of naming compounds. We will always use: There are two main types of chemicals to name: 1. 2. IONIC: Writing Formulas: ⚫ Write the symbols of both elements or ions in the name with their valences. ⚫ Cross down the valence numbers (in absolute value) ⚫ Factor those numbers, if possible Calcium Fluoride Aluminum Oxide Zinc Sulfide Tin (IV) Oxide Potassium Nitride Copper (II) Phosphide Naming: ⚫ Write the name of the first element ⚫ Check to see if that element has more than one valence. ⚫ If it only has one, do not add the valence. ⚫ If it has more than one, find the valence and add it in brackets with a roman numeral. ⚫ Write the name of the second element with an ide ending. BaCl2 Ag3N RbBr Na2O AlP CuCl2 AuN OUS/IC NAMING SYSTEM: ⚫ Older system but some old scientists still use it. ⚫ Only used for multivalent metals ⚫ The higher valence will have an ic ending ⚫ The lower valence will have an ous ending ⚫ You will never name them, but you may be given the name and need to write the formula  3 SCH3U Stannic Chloride element): Naming: Mercurous Nitride Plumbous Phosphide Cupric Manganic Oxide Fluoride Nomenclature of Acids: Ferrous Iodide Binary Acids (only H and an Write hydro before the element and give it an ic acid ending. ⚫ Example: ⚫ HCl ⚫ HBr ⚫ HF ⚫ HI OXY ACIDS: Hypoiodous acid Carbonous acid Fluorous acid Pernitric acid Bromic acid Hypophosphorous acid HClO H2SO2 H3PO5 HBrO HNO2 HIO4 H2CO3 HClO3 Sulphuric acid Perchloric acid  4 SCH3U OXY ACID RADICALS: Copper (II) Bromite Magnesium Hypobromite Zinc Phosphate Strontium Perchlorate Silver Hypocarbonite Nickel (II) Carbonite Manganese (II) Persulfate Calcium Hypoiodite NH4SO4 Mg(OH)2 Fe(MnO4)2 Ba(CN)2 CaCO3 KC2H3O2 Hg3PO2 AlPO5 Examples: Tin (IV) Pernitrate Gold (III) Phosphite Other ions you are required to memorize: : ⚫ Hydroxide * CuSO4 5H2O is a ⚫ Ammonium Sodium Hydroxide ⚫ Acetate Ammonium Chloride Beryllium Acetate HYDRATES: * To name a hydrate, name the first compound as usual * Then, write the PREFIX that gives the number of water molecules, and add “hydrate” to it  * The name of CuSO4 5H2O is: * 5 SCH3U * Try naming: * Mg3(PO4)2 7H2O * KNO3 3H2O * Formulas for: * Copper (I) sulphate octahydrate * Iron (III) chlorate hexahydrate COVALENT NOMENCLATURE: Memorize the following prefixes: 16 27 38 49 5 10 Formulas: Write the symbol of the first element Write the amount of that element as given by the prefix in the name (if there is no prefix, there is one) Write the symbol of the second element Write the amount of that element as given by the prefix in the name Carbon monoxide Silicon Nitrogen trihydride tetrahydride Selenium dioxide Phosphorus pentachloride Sulphur hexafluoride Naming: Write the prefix for the first non-metal if there is more than one of it Write the name of the first element Write the prefix of the second element Write the name of the second element CBr4 PCl5 CO CH4 N2O4 Cl2O HOMEWORK: Work on the naming package, but FINISH the binary/multivalent metals. IONIC (binary/multivalent metal) compounds QUIZ. 6