Ions Ions: A charged particle formed when a neutral atom or group of atoms gain or lose one or more electrons. Example Na Na+ + eF + e- F1 Cations Mg Mg2+ + 2eAl Al3+ + 3eCation: A positively-charged ion. One or more electrons are lost from a neutral atom oxidation 2 Anions I + e - IO + 2e- O2S + 2e- S2Anion: A negatively-charged ion. Electrons are gained by a neutral atom reduction 3 Ions Ion charges can be predicted from the Periodic Table Main Group metal (IA-IVA) ion-charges correspond to group number Main Group non-metal (IIIA-VIIIA) ion-charges correspond to (group# - 8) Sodium (Na) in IA +1 Fluorine (F) in VIIA (7-8) = -1 All this has to do with electron configuration See website as well: http://web.clark.edu/aaliabadi/phSC106_ions%20shee t.htm 4 Compounds That Contain Ions Require metal and non-metal Form ionic bonds Called an ionic compound Characteristic Properties 1. Very high melting points 2. Conduct an electric current when melted or when dissolved in water 5 Ionic compound The number of cations and anions must have a net charge of zero. 6 Compounds that Contain Ions Writing Formulas for Ionic Compounds Give the formulas for the compounds that contain the following pairs of ions: (a) K and I (b) Mg and N 7 Naming Ionic Compounds 1. The cation is always named first and the anion second. 2. The cation takes its name from the name of the element. 3. The anion is named by taking the first part of the element name and adding –ide. 8 Naming Ionic Compounds Name the following Type I compounds NaCl RaBr2 Rb2O AlI3 K3N Cs4Si Give the chemical formula for the following Type I compounds Strontium phosphide Calcium fluoride Beryllium carbide Lithium hydride Barium sulfide Magnesium telluride 9 Naming Ionic Compounds Type II compounds need to be identified by a Roman numeral (I), (IV), etc. Represents oxidation state of cation Not how many cations are present in compound! Example: NaCl sodium (I) chloride is INCORRECT Example: SnCl4 tin (IV) chloride is correct 10 Naming Ionic Compounds Type II Ionic Compounds FeCl2 and FeCl3 PbO and PbO2 MnS and Mn2S7 11 A Mixed Bag PbBr2 and PbBr4 Aluminum arsenide FeS and Fe2S3 Thallium (III) boride Mercury (II) carbide Na2S CoCl3 Cerium (IV) phosphide ScF3 Gold (I) selenide Vanadium (V) telluride 12 Naming Compounds that Contain Polyatomic Ions Polyatomic Ion: An ion that contains more than one atom. They are charged entities composed of several atoms bound together. Consult my website for the list: http://web.clark.edu/aaliabadi/phSC106_ions% 20sheet.htm 13 Caveat Parenthesis required if more than one polyatomic ion present Ca(ClO)2 is correct Ca(I)2 is INCORRECT 14 Naming Compounds that Contain Polyatomic Ions Name or provide the chemical formula for each of the following compounds: (a) Ca(OH)2 (e) Co(ClO)2 (b) Sodium phosphate (f) platinum (IV) bicarbonate (c) KMnO4 (g) Cu(NO2)2 (d) Ammonium nitrate (h) nickel (III) oxide 15 Naming Compounds that Contain Polyatomic Ions Name or provide each of the following compounds: (a) calcium carbonate (e) MoO (b) BaSO4 (f) Iridium (VII) acetate (c) CsClO (g) ZnCl2 (d) Zirconium sulfite (h) lithium cyanide 16 Naming Acids Acids: A substance that yields hydrogen ions (protons, H+) when dissolved in water. HCl(aq) H+(aq) + Cl-(aq) H3PO4(aq) 3H+(aq) + PO43-(aq) 17 Rules for naming acids If the formula does not contain oxygen the prefix of the acid is hydro and the suffix –ic is attached to the root name for the element. Ex: HCl = hydrochloric acid, H2S = hydrosulfuric acid When the anion contains oxygen, the acid name is formed from the anion name. The suffix –ic or –ous is added. When the anion ends in –ate, the suffix –ic is used. H2CO3 = carbonic acid When the anion ends in –ite, the suffix –ous is used. H2SO3 = sulfurous acid 18 Naming Compounds that Contain Only Nonmetals: Type III Compounds containing only nonmetals: Form covalent bonds share electrons Rules for Naming Type III Binary Compounds 1. The first element in the formula is named first, and the full element name is used. 2. The second element is named as though it were an anion. 3. Prefixes are used to denote the numbers of atoms present. 4. The prefix mono- is never used for naming the first element. 5. Drop the “a” when it is followed by an “o” Tetraoxide should be tetroxide 19 Naming Compounds that Contain Only Nonmetals: Type III Prefixes Used to Indicate Numbers in Chemical Names Prefix Number Indicated mono1 di2 tri3 tetra4 penta5 hexa6 hepta7 octa8 nona9 deca10 20 Practice CCl4 Silicon dioxide NO2 Sulfur trioxide P2O5 Iodine pentafluoride Dinitrogen tetroxide SeI2 Xenon hexafluoride 21 The Name Game Extra credit opportunity Mix-and-match 22