Ch. 6 Chemical Names and Formulas Distinguish between chemical formulas, molecular formulas, and formula units Distinguish between ionic and molecular compounds Define cation and anion and relate them to metal and nonmetal Define polyatomic ion and give the names and formulas of the most common polyatomic ions Apply the rules for naming and writing formulas for ionic compounds Apply the rules for naming and writing formulas for molecular compounds Name and write the formulas for common acids

Types of Chemical Formulas Distinguish between chemical formulas, molecular formulas, and formula units Chemical Formulas Show the kinds and number of atoms in the smallest representative unit of a substance Types of Chemical Formulas Monatomic formulas Single atom, formula is their atomic symbol (He, Ne) Diatomic formulas Two atoms There are 7 (H2, F2, N2, O2, Cl2, Br2, I2)

Distinguish between chemical formulas, molecular formulas, and formula units Shows the kinds and numbers of atoms in a molecule of a compound (covalent) Ex: H2O (water, two hydrogen atoms, one oxygen atom) NH3 (ammonia, one nitrogen atom, three hydrogen atoms)

Distinguish between chemical formulas, molecular formulas, and formula units Ionic Compounds The chemical formula does not represent a molecule Ionic solids are positive and negative ions arranged in continuous arrays The formula unit represents the lowest number ratio of ions in the compound

Distinguish between ionic and molecular compounds Ionic Compounds Made up of cations and anions Cations: positive ions, metals Anions: negative ions, nonmetals Ex: NaCl Na+ (cation) Cl- (anion)

Define cation and anion and relate them to metal and nonmetal Monatomic Cations (one atom) Element Cation Charge Aluminum Al3+ 3+ Barium Ba2+ 2+ Hydrogen H+ 1+ Silver Ag+ Sodium Na+

Define cation and anion and relate them to metal and nonmetal Monatomic Anions (name ends in -ide) Element Anion Charge Chloride Cl- 1- Oxide O2- 2- Nitride N3- 3-

Define cation and anion and relate them to metal and nonmetal Oxidation State when an atom loses electrons, it is said to be oxidized Oxidation of an atom may have nothing to do with oxygen, some metals have more than one oxidation state

Define cation and anion and relate them to metal and nonmetal Formula Charge Classical Name Iron (II) Fe2+ 2+ Ferrous Iron (III) Fe3+ 3+ Ferric Chromium (II) Cr2+ Chromous Chromium (III) Cr3+ Chromic Tin (II) Sn2+ Stannous Tin (IV) Sn4+ 4+ Stannic

Define polyatomic ion and give the names and formulas of the most common polyatomic ions Polyatomic Cations (more than one atom) Cation Formula Charge Ammonium NH4+ 1+ Mercury (I) Hg22+ 2+

Define polyatomic ion and give the names and formulas of the most common polyatomic ions Polyatomic Anions: name ends in -ite or -ate Anion Formula Charge Carbonate CO32- 2- Bicarbonate HCO3- 1- Nitrite NO2- Nitrate NO3- Sulfate SO42-

Apply the rules for naming and writing formulas for ionic compounds Binary Ionic Compounds – Name Ends in “ide”. Two types of atoms (different elements) May have more than one atom of each element Balance cations with anions Ex: Sodium chloride Na+ + Cl- NaCl Iron (III) oxide _Fe3+ + _O2- Fe2O3

Apply the rules for naming and writing formulas for ionic compounds Ternary Ionic Compounds – Name of the “polyatomic anion” Three types of atoms (different elements) Ex: Sodium carbonate Na+ + CO32- Na2CO3

Apply the rules for naming and writing formulas for ionic compounds Quaternary Ionic Compounds – Name of the “polyatomic anion”. Four types of atoms (different elements) Ex: Ammonium sulfate NH4+ + SO42- (NH4)2SO4

Apply the rules for naming and writing formulas for ionic compounds Ionic Naming Rules the cation is always named first name does not change the anion is named second anion is monatomic add –ide anion is polyatomic add –ate or –ite (check chart) LiCl Lithium chloride Sn(NO3)4 Tin (IV) nitrate Stop go to Ionic Naming handout

Binary Molecular Compounds Apply the rules for naming and writing formulas for molecular compounds Binary Molecular Compounds Composed of two nonmetallic elements Ionic charges are not used to assign formulas or names Elements often combine in a number of different ways

Binary Molecular Compounds Apply the rules for naming and writing formulas for molecular compounds Binary Molecular Compounds Carbon and Oxygen Formula Form Carbon dioxide CO2 Gas Carbon monoxide CO Poison Gas Carbonate CO32- Anion Oxalate C2O22-

Binary Molecular Compounds Apply the rules for naming and writing formulas for molecular compounds Binary Molecular Compounds Prefixes tell how many atoms of each element are present in each molecule Prefix Number Mono- 1 Hexa- 6 Di- 2 Hepta- 7 Tri- 3 Octa- 8 Tetra- 4 Nona- 9 Penta- 5 Deca- 10

Binary Molecule Compounds Apply the rules for naming and writing formulas for molecular compounds Binary Molecule Compounds If there is a single atom of the first element in the name, omit the mono- Ex: Carbon dioxide, not monocarbon dioxide The second element in the name ends with -ide Sometimes a vowel gets dropped when the prefix is added Ex: monoxide not monooxide

Apply the rules for naming and writing formulas for molecular compounds Naming Common Acids Formula: anions connected to as many hydrogen ions as required to make electrically neutral Acid formed from halogens (F, Cl, Br) use the prefix hydro- EX: HCl hydochloric acid; HF hydrofluoric acid Acid names drop the -ate or -ide from the anion and add -ic acid -OR- drop the -ite and add -ous

Apply the rules for naming and writing formulas for molecular compounds Acid Formula Anion Hydrogen Ions Hydrochloric acid HCl Cl- 1 H+ Hydrofluoric acid HF F- Sulfuric acid H2SO4 SO42- 2 H+ Sulfurous acid H2SO3 SO32- Nitric Acid HNO3 NO3- Acetic Acid HC2H3O2 C2H3O2- Phosphoric acid H3PO4 PO43- 3 H+ Carbonic Acid H2CO3 CO32-

second atom gets prefix and –ide at the end CO2 carbon dioxide Apply the rules for naming and writing formulas for molecular compounds Covalent Naming Rules if first atom is monatomic do not add a prefix, if polyatomic add a prefix second atom gets prefix and –ide at the end CO2 carbon dioxide Cl2O dichlorine monoxide

Use your chart and pg. 147 for help with naming Apply the rules for naming and writing formulas for ionic and molecular compounds PRACTICE PROBLEMS Pg. 166 54, 56, 58, 61, 62, 64-66 Use your chart and pg. 147 for help with naming