Chem 103 1st Edition Exam 1 Study Guide Lectures 1 10 Lecture 1 January 26 The fundamental idea of chemistry is the properties of matter that we see smell and feel are result of properties of atoms and molecules An atom is the smallest particle that still has properties of matter Molecules are two or more atoms that are chemically combined Matter takes up space has volume and has mass Lecture 2 January 28 Physical properties are something you can observe without changing the composition of the sample Chemical properties are things you observe during chemical reactions Kelvin Celcius 275 15 Fairenheight 9 5celcius 32 Volume is how much space a sample takes up and is length width height Lecture 3 January 30 Density is how much substance is present in a certain volume and is mass over volume Density is an intensive property Intensive properties are the same regardless of sample size Extensive properties differ from sample to sample Density of a substance can be used to identify an unknown A conversion factor is a relationship that s physically equal to 1 1 inch 2 54 centimeters Lecture 4 February 2 In the 1800 s John Dalton developed the atomic theory based on three laws law of conservation of mass law of constant proportions and law of multiple proportions Atoms are comprised of a dense nucleus where protons and neutrons lie the electrons are in different shells around the nucleus Electrons were discovered by JJ Thompson using a cathode ray tube He said the particles must be present in all materials and negatively charged Rutherford used a golf foil model to determine more about the atoms He said that most of atoms mass and all of its positive charge are in the nucleus most of the volume of an atom is empty space with a few negatively charged electrons and the number of electrons equal the number of protons in the nucleus Elements are atoms with the same number of protons The atomic number is the number of protons Isotopes are atoms of the same element with different number of neutrons The mass number is the number of protons and neutrons Lecture 5 February 4 Ions are atoms of the same element that have gained or lost electrons There are two types of electrons cations are positively charged while anions are negatively charged Dimitri Mendeleav noticed certain groups of elements have similar properties The periodic law is when atoms are arranged by increasing mass sets of properties occur periodically Lecture 6 February 6 A mole is 6 022 10 23 of any objects mostly atoms in chemistry A compound is two or more elements that can t be separated by physical means Most pure elements have the same formula as their symbol There are 7 diatomics 2 atoms per molecule they are H O F Cl Br I and N There are two types of bonds Ionic bonds are where electrons are transferred between the two atoms covalent bonds are where electrons are shared between the two Lecture 7 February 9 Compounds of only non metals are molecular where compounds of a metal and nonmetal are ionic When naming compounds you have to identify if it s ionic or molecular first Acids to remember are HCl hydrochloric acid HNO3 nitric acid H2SO4 sulfuric acid Lecture 8 February 11 The names of acid depend on the name of the anion Anions ending with ide can be formed to acids with hydro and ic Anions ending with ate can be formed to acids with ic Ions ending with ite can be formed to acids with ous When naming binary molecule compounds three rules apply furthest element to the left is named first if they are in the same column the lower one goes first and the second element is given an ide ending The molar mass of compounds is an extension of the molecular example The percent composition mass percent is calculated by mass of the element in 1 mole of the compound over mass of one mole of the compound itself Lecture 9 February 13 You can use the chemical formula to determine the amounts of each element The empirical formula is the smallest whole number ratio of elements in a compound The molecular formula tells the number of each type of atom in the molecule To tell if the formula is empirical or molecular you look at the mole ratios To determine the molecular formula of a compound you need the empirical formula and the molar mass of the compound Lecture 10 February 16 Combustion is the process of burning something in oxygen gas Hydrocarbons are compounds made up of hydrogen and carbon Combustion of hydrocarbons give the same products CO2 and H2O Combustion gives us an introduction to stoichiometry Stoichiometry answers questions like how much product is in a reactant And how much reactant is produced