Chem 111 1nd EditionExam # 1 Study Guide Lectures: 1 - 7Lecture 1 (January 14th)Intro to Chemistry:Key Terms:Science – Knowledge, specifically, knowledge that is acquired through experience or experimentation.Chemistry – The study of matter and it’s interactions with energy and other matter.Physical Properties: Can be measured without changing the composition of the sample.- Mass, density, color, melting point.Physical Change – A change that occurs without altering the composition of a material.- Freezing, meltingChemical Properties – Describe the reactivity of a material.- Natural gas burns in air; iron rusts.Chemical Change – At least part of the material is changed into a different kind of matter.- The digestion of sugar is an example.Substances – A material that is chemically the same throughout. Cannot be separated into component parts by physical methods.- There are two different types of substances. - Elements – cannot be broken into simpler substances.- Compounds – Can be broken down into elements. (by chemical methods)Mixture – Matter that can be separated into simpler materials by physical methods.- Heterogeneous mixture - composition of the mixture changes from one part to another.- Homogeneous mixture (or solution) – Composition of the mixture is uniform throughout- Alloy – A solution of a metal and another material (usually another metal)Lecture 2 (January 16 th )Accuracy - Agreement of a measurement with the true value.Precision – Agreement among repeated measurements of the same quantity.Significant Figures: The number of significant figures is the number of digits from the first non-zero digit through the last reported digit.- The uncertainty is at least +/- 1 unit in the last reported digit.- Zeros preceding the first non-zero digit are not significant.- A zero is only significant if preceded by a non-zero digit.Ex: How many significant figures are in each of the following?0.0012 (2)106 (3)900.0 (4)1.0012 (5)0.001060 (? Try it! ?)Base Units in the SIQuantity Unit AbbreviationLength Meter mMass Kilogram kgTime Second sTemperature Kelvin K Amount Mole molElectric Current Ampere ALuminous Intensity Candela cdCommon Prefixes Used with SI UnitsPrefix Abbreviation MeaningMega- M 106Kilo- k 103Centi- c 10-2Milli- m 10-3Micro- u 10-6Nano- n 10-9Pico- p 10-12Lecture 3 (January 21st)Molecular Compound: When two or more elements form a molecule.- Molecular compounds typically form from nonmetals.Molecular Formula: A formula that gives the number of every type of atom in each molecule.- Subscripts used to express charge in molecule.Structural Formula: Shows which elements go into the structure of the molecule.Molecular Mass: The sum of the atomic masses of all the atoms, expressed in atomic mass units(u).Ex: Calculate the molecular mass of ammonium (NH4+)N (14.007 u) = 14.007 uH (1.008 u) 1.008 x 4 = 4.032 uAdd these two sums together to get the molecular mass of ammonium (18.038 u)Ionic Compounds: An ionic compound is composed of cations and anions forming a neutral species.- The formula of an ionic compound is an empirical formula that uses the smallest whole number as the subscript.- The relative numbers of ions in the empirical formula balances the charge to zero.- Positioning of an element on the periodic table can help determine the elements charge.(Ex: Oxygen2-, Sulfur2-)Polyatomic Ion: A group of atoms with a net charge that behaves as a single particle.- An example of a polyatomic ion is ammonium.- Barium and Nitrate - Ba2+(NO3-)2- Ammonium and Sulfate - (NH4+)2SO42-Formula Mass: The sum of the atomic masses of all the atoms in the empirical formula for an ionic compound.Chemical equation: A shorthand notation to describe a chemical reaction.- 2Mg+O2 -------------> 2MgO (Magnesium Oxide)Reactants of the chemical reaction are the substances that are consumed.Products of the chemical reaction are the substances that are formed.Balancing Equations:H2+Cl2 ---------> HCl (Unbalanced)Add coefficients so the # of atoms on each element is the same on both sides of the equationH2Cl2 -------> 2HCl (Balanced)C5H12+O2 -------> CO2+H2O (Unbalanced)C5H12+O2 -------> 5CO2 + 6H2O (Not completely balanced)C5H12 + 8O2 --------> 5CO2 + 6H2O (Balanced)When balancing equations, fractional coefficients may be obtained.C5H10+15/2O2 -----------> 5CO2 + 5 H2OMultiply all coefficients by the denominator. (2 in this case)2C5H10+15O2 ------------> 10CO2 + 10 H2OLecture 4 (January 23 rd )Neutralization: The reaction of an acid with a base to form a salt and water.Example of Neutralization:HCl + NaOH --------------> NaCl + HOH Acid Base Salt WaterRule: The number of hydrogen ions provided by the acid must equal the number of hydroxide ions provided by the base.Combustion Reactions: The process of burning. Any chemical reaction that includes burning is acombustion reaction. - Most of these are the combination of a substance and oxygen.- When hydrocarbon burns in oxygen, the carbon is converted to CO2 and the hydrogen forms water (H2O)(CH3)2O + O2 --------> C2H6OSalt: An ionic compound consisting of the cation of a base and an anion of an acidOxidation- The loss of electrons by a substance in a reaction.Oxidation-Reduction Reaction- A reaction in which electrons are transferred from one species to another.Oxidation Number- Can be assigned to each number depending on a set of rules… - An atom in its elemental state has oxidation number of 0.- The oxidation number of monoatomic ions is the charge of the ion.- The sum of the oxidation numbers in any species must equal the charge of the species.Reduction- The gain of electrons by a substance in a reaction.Oxidation States:Reactant --------> ProductNa=0 -------> Na+= +1 OxidationCl in Cl2 = 0 ------> Cl- = -1 ReductionConverting Moles to EntitiesMolar Mass: The molar mass (M) of any atom, molecule, or compound is the mass ingrams for exactly one mole of substance.Converting Moles and MassHow many moles of Ethylene, C2H4 are present in 16 g of that compound?About .57 moles Molar mass of C2H4 is about 28.Mass Percentage from FormulaSubscripts in formula x atomic mass / molar mass x 100Lecture 5 (February 4 th )Molecular Formula: The molecular formula must be a whole multiple of the empirical formula.- If the empirical formula is CH2, the molecular formula is (CH2)n wheren = molar mass of compound / molar mass of empirical formulaEx: A compound has the empirical formula