General Chemistry Study Guide 1 Chemistry study of matter energy and energy ow which accompanies both physical and chemical change 1 Energy ability to do work A Thermal Light Electrical Nuclear 2 Matter anything which has mass and volume solid liquid gas A Pure Substance material w xed composition i Element comprised of 1 type of atom ii Compound comprised of 2 or more different elements in a xed ratio by mass Molecule 1 or more atoms which are covalently bonded Diatomic elements Br2 I2 N2 Cl2 H2 O2 F2 B Mixture a group of two or more substances which are physically intermingled i Homogeneous components uniformly distributed throughout ii Heterogeneous components non uniformly mixed Newton s Second Law F ma Newton kilogram x meter second 2 Density d m v Work w Fd joule Newton x meter Temperature Kelvins Celsius 273 15 History of Atomic Theory Democritus matter is composed of individual indivisible units atomus indivisible Aristotle universe is comprised of four elements Air Water Fire Earth Lavoisier Law of Conservation of Mass matter can t be created or destroyed Praust Law of De nite Composition Constant Proportions a chemical compound is Dalton Law of Multiple Proportions elements combined in different ratios create consistently comprised of the same elements in the same ratios different compounds Atomic Theory 1 matter is comprised of atoms 2 atoms are indivisible 3 atoms of one element are identical 4 atoms of one element can t be converted to another element 5 compounds result when different atoms combine Thomson Cathode Ray Tube negative particles in a vacuum reacted to applied electrical magnetic eld determined charge to mass ratio of an electron Plum Pudding atomic model electrons uniformly distributed throughout a positively charged medium Coulomb s Law opp charges attract like charges repel Millikan Oil Drop Experiment negative charged oil droplets watched how fast they fell or if they suspended in air when an electric eld was applied calculated actual charge mass of e 1 602 x 10 19 C 9 109 x 10 28 g Rutherford Gold Foil Experiment positive alpha particles shot at gold foil some passed through some bounced back therefore must be a positive core Chadwick Beryllium Experiment hit beryllium with alpha particles emitting neutral discovered positive charged nucleus e s charge of nucleus concluded that majority of atom is empty space charged rays discovered neutron modern atomic model A atomic mass protons neutrons Z atomic number protons X element symbol P N neutral element Appearance Malleability Taste Electrical Conductivity Thermal Conductivity avg atomic mass abundance1 x isotope mass1 a2m2 Ion charged particle anion cation Formula Unit simplest representative unit of an ionic compound Isotopes different forms of elements dependent on number of neutrons Atomic Mass Unit 1 12 mass of Carbon 12 atom Mass Spectrometry instrument used to determine percent abundance Mass Spectrum percent abundance vs mass bar graph Physical Properties attributes detected with senses Density Ductility Physical Change form or phase change Chemical Properties behaviors when exposed to change Readily Dulls Chemical Change composition change Evidence of Chemical Reaction reactants products Temperature Change Law of Conservation of Energy energy is neither created nor destroyed Melt Freeze Vaporization Condensation Sublimation s g Deposition g s Combustibility Precipitation Formation Acid Base Neutralization Oxidizes Exothermic energy is released to surroundings Endothermic energy is absorbed from surroundings Color Change Precipitate Formation Gas Evolution SI Units meter kilogram second ampere kelvin mole Signi cant Figure Rules 1 all non zero 2 zeros between non zeros 3 zeros after decimal point 4 addition and subtraction round up to weakest link least precise decimal 5 multiplication and division round up to least number of sig gs 6 rounding if removed digit is 5 odds round up evens remain place Covalent Bonds sharing of electrons between two non metals elements Nomenclature of Binary Molecular Compounds Covalent Bonds 1 add pre x to respective elements no pre x added to rst element if it s mono 2 lower group number higher period number if same group named rst 3 add suf x to second element ide Ionic Bonds give take of electron s between a metal cation and a non metal anion Nomenclature of Binary Ionic Compounds Ionic Bonds electrostatic attractions 1 cation named rst w roman numeral if transition metal Sn or Pb 2 anion named second with suf x ide if monatomic polyatomic as is Polyatomic Anions O4 per ate O3 ate ite O2 O hypo ite exceptions CrAsPS O4 ate O3 ite Nomenclature of Acids Monatomic anions Polyatomic anions H hydro ic acid H ite ous acid ate ic acid e g he bITE and said it was deliciOUS she ATE the whole cake and felt sICk Nomenclature of Hydrates ionic compounds w water molecules per formula unit 1 name ionic compound 2 add pre x to hydrate corresponding to number of molecules Stoichiometry Mole number of entities equal to the number of atoms in 12 grams of Carbon 12 Avogadro s number 6 02 x 1023 Molar Mass g mol Gas Volume 1 mol at STP 273K 1atm 22 4 L Classifying Simple Chemical Reactions 1 Combination Synthesis two or more pure substances unite to form a more complex pure substance 2 Decomposition A more complex substance disintegrates into one or more A B AB different pure substances 3 Combustion reactions of any compound with O2 AB A B CH4 2O2 CO2 2H2O Complete combustion of a hydrocarbon yields CO2 H2O resulting a compound separation of the other element 4 Single Displacement One element takes the place of another element 5 Double Displacement partner swapping between ions A BC AC B AB CD AD CB Empirical Formula the formula containing the simplest numerical ratio between the elements in a compound Molecular Formula the formula containing the actual number of elements in a single molecule Determining Formulae Empirical Formula 1 replace with grams 2 convert elements to moles 3 insert moles as subscripts in the formula divided by the smallest calculated mole Molecular Formula 4 divide given molar mass by the empirical mass use the quotient as the coef cient of value the empirical formula Combustion Analysis 1 convert mass of CO2 to mass of C 2 convert mass of H2O to mass of H 3 nd mass of O by subtracting C and H from original sample mass 4 convert all grams to moles 5 determine formulae with subscripts CHO Mixture Composition Determination 1 separate mixture using x and x 2