January 11 2013 Chemistry Notes Chapter 2 Elements Element Simplest type of matter composed of only one kind of atom o Cannot be broken down into a simpler substance Compound Composed of one or more elements that are chemically bonded together o Always made up of the same number and type of element Mixture Two or more substances either elements or compounds that are physically mixed o Can vary in composition Chapter 2 2 Law of Conservation of Mass Total mass does not change o Matter is not created nor destroyed 180 g of glucose 192 g oxygen 264 g carbon dioxide 108 g water 372 g 372 g Definite Composition Composition of a compound does not change Mass of an Element mass of the element divided by the mass of the compound multiplied by one hundred Law of Multiple Proportions When two or more elements combine they do so in whole number ratios the ratios can be different Recitation wetzelcollin gmail com Periodic Table Predicting Ions Gain or lose electrons to be like the nearest noble gas column 18 Compounds Ionic o Coulomb s law energy is proportional to the charge of 1st ion times the charge of 2nd ion divided by distance Higher charges more strongly attracted Smaller the ion the more strongly attracted they are Forming Ionic Compounds o Neutral Has no charge o Positive Negative o Formula Unit smallest collection of ions that is neutral Ex Ca 2 O 2 CaO Ex K 1 S 2 2K 2 S 2 K2S Ex Al 3 O 2 2Al 6 3O 6 Al2O3 Pp As 3 Ca 2 2As 6 3Ca 6 As2Ca3 Naming Ionic Compounds o Cation anion o Name of cation name of anion with ending changed to ide Ex MgCl2 Magnesium Chloride Ex K2O Potassium Oxide Formula for Calcium Sulfide Ca 2 S 2 CaS Metals with more than one charge o Transition Metals Told what the charge is o Ex Fe 3 Cl 1 Fe 3 3Cl 3 FeCl3 o Must indicate charge in name Put charge after name in parenthesis using roman numerals Ex FeCl3 iron III chloride o Parenthesis always tells you the charge not the number of ions Ex VCl2 V 2Cl 2 V 2 2Cl 2 Vanadium II chloride Use ic and ous endings table 2 4 Iron 3 or 2 o Higher charge ic o Lower charge ous latin o Ferric Fe 3 o Ferrous Fe 2 Polyatomic Ions Table 2 5 DO NOT MEMORIZE A group of atoms with a charge o Work the same way as monoatomic ions When using them in a name do NOT change the name of polyatomic ion o Ex Compound formed from ammonium and bromide NH4 1 Br 1 NH4Br o Formula for Aluminum Nitrate Al 3 NO3 1 Al 3 3NO3 3 Al NO3 3 Binary Acids o Hydrogen Non metal o Hydro name of non metal changed to ic acid o HCl Hydrochloric Acid o H2S Hydrosulfuric Acid Oxy Acids o Hydrogen Polyatomic Ion o Name of polyatomic ion changed To ic if ending is ate To ous if ending is ite o H2SO4 Sulfuric Acid o HNO2 Nitrous Acid Acids