Chemistry Chapter 10 Notes #1

Covalent Compounds -Review  Common Diatomic molecules Hydrogen (gas), Oxygen, Nitrogen, Fluorine, Chlorine, Bromine, Iodine  Acids – Binary and Oxy Hydrochloric, Hydrosulfuric, Sulfuric, Sulfurous, Chlorous  Regular Compounds Carbon Dioxide, Carbon tetrachloride, diphosphorus pentoxide

Covalent Compounds  Nonmetal + nonmetal  Use prefixes to tell how many of each (find it on the pink sheet)  2 nd element, change the ending to –ide Example Fluorine becomes Fluoride  Example: CO 2 - Carbon Dioxide  Example: N 2 O 4 – dinitrogen tetraoxide

Ionic Compounds - Review  Cation + Anion (positive + negative) Charges matter!!!!!! Roman numerals tell charge for transitions Polyatomics don’t end in –ide (mostly) Need your cheat sheet  Examples Tin (IV) oxide, lead (II) sulfite, strontium carbonate, aluminum oxide, magnesium chloride, calcium oxide, potassium iodide, potassium iodate

Ionic Compounds  Metal + nonmetal  Find charge on periodic table for elements, on pink sheet for polyatomics  Ions come together to balance charge  NO charges (superscripts) in the formulas, just subscripts  EX: Mg 2+ and Cl - = MgCl 2  Name: Name the metal, change the nonmetal ending to –ide  EX: MgCl 2 = Magnesium Chloride

Chemical Reactions- Review  Change in the composition and properties of a substance, or substances, as the result of a chemical reaction. Ex. Souring of Milk Ex. Rusting of iron Ex. Change in color Burning./Combustion  Chemical reactions change substances

Chemical Reactions- Review  Signs of Chemical Change Combustion (Flame, Smoke, Ash) New substance formed  Color change  Precipitate (solid formed when mixing 2 liquids) Bubbling/fizzing (Production of a gas) Change in Temp (warmer or cooler) Disappearance of a metal Formation of liquid droplets Odor

Reactions  Breaking bonds require energy  Forming bonds releases energy  2 terms for describing the overall energy transfer in a chemical reaction Exothermic Endothermic Reactions

Chemical Reactions  Exothermic Reactions Chemical reactions that overall release energy  They use energy to break bonds, but more energy is released in the formation of the products than was used to break the bonds Endothermic Reactions Chemical reactions that overall use energy They use more energy to break bonds than is released in the formation of the products

Chemical Reactions Exothermic Endothermic

Chemical Reactions  Original bonds are broken  Atoms rearrange  New bonds form  Reactants: starting substances that will undergo a chemical change  Product: substance that is the result of a chemical change/reaction

Chemical Reactions  Energy is conserved in chemical reactions Law of conservation of energy  Chemical energy – energy stored in the bonds of the compounds  Total energy on the reactant side of an equation equals the total energy on the product side  This includes the energy given off….

Chemical Reactions  Reactants -> Products  Word Equation Isooctane + oxygen -> carbon dioxide + water  Skeleton Equation C 8 H 18 + O 2 -> CO 2 + H 2 O  Chemical Equation 2C 8 H O 2 -> 16CO H 2 O

Chemical Reactions  In a balanced chemical equation energy and mass is conserved  You can only change coefficients NO CHANGING SUBCRIPTS! Changing the subscripts changes the chemicals, therefore it changes the entire reaction  Changing coefficients is just changing the amounts of chemicals necessary to carry out the reaction