Popular in Chemistry 1
Popular in Chemistry
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Date Created: 02/01/15
Chapter 1 Matter Measurement and Problem Solving 82614 0 Atoms O smallest indestructible item 0 Molecule 0 2 or more atoms attached together in a specific geometrical arrangement 0 bond attachment bw 2 atoms to make molecules 0 Chemistry seeks to understand the behavior of atoms and molecules 0 Matter anything that takes up space and has a mass 0 classified based on its state and its composition solid liquid gas 0 also classified into pure substances and mixtures l pure substances element and compoundseperable l mixture heterogeneous and homogeneousuniform 0 properties of matter I physical characteristics of matter that can be changed without changing composition observable 0 physical changes boiling of water molecules separated but composition and structure do not change I chemical characteristics that determine how the composition of matter changes as a result of contact with other matter or the influence of energy 0 chemical changes in matter rusting of iron iron atoms in nail combine with oxygen to make a new substance rust with a different composition burning dyes fading or changing color usually nonreversible 0 Standard units 0 Scientists have agreed on a set of international standard units for comparing all our measurements called the SI units 0 Mass amount of matter present in an object 0 Temperature fahrenheit celsius kelvin fig 11 for conversions 0 volume derived unit I any length cubed I cubic meter l commonly measure liquid or gas in milliliters 1000 mLin1L100mLin1m3 0 Intensive and extensive properties 0 extensive properties properties whose value depends on the quantity of matter 0 intensive properties value is independent of the quantity of matter 0 Density ratio of mass to volume 0 intensive property 0 volume of a solid can be can be determined by water displacement O solidgtliquidsgtgtgtgas except ice is less dense than liquid water 0 Significant Figures 0 addition or subtraction answer cannot have more digits to the right of the decimal point than any of the original numbers 0 multiplication or division of sig figs in the result is set by the original number that has the smallest number of sig figs 0 exact numbers numbers from definitions or numbers of objects are considered to have an infinite number of sig figs 0 Dimensional analysis 0 1 Determine which unit conversion factors are needed 0 2 Carry units through calculation 0 3 If all units cancel except for the desired units then the problem was likely solved correctly Chapter 2 Atoms and Elements 0 Law of Conservation of Mass 0 matter neither created nor destroyed 0 because only whole atoms combine and atoms are not changed or destroyed in the process the mass of sodium chloride made must equal the total mass of sodium and chlorine atoms that combine together 0 Dalton s Atomic Theory 0 Dalton proposed a theory of matter based on it having ultimate indivisible particles to explain the Laws of Definite and Multiple Proportions 0 Each element is composed of tiny indestructible particles called atoms 0 All atoms of a given element have the same mass and other properties that distinguish them from atoms of other elements 0 Atoms combine in simple wholenumber ratios to form molecules of compounds 0 In a chemical reaction atoms of one element can not change into atoms of another element 0 Elements 0 Each element has a unique number of protons in its nucleus 0 The number of protons in the nucleus of an atom is called the atomic number 0 Each element has a unique name and symbol 0 ion atom with a net positive or negative charge 0 cation atom with a positive charge anion atom with a positive charge monatomic ion contains only one atom Ordered elements by atomic mass 0 O Q Mandeleev O 0 Saw a repeating pattern of properties 0 Periodic Lay when the elements are arranged in order of increasing atomic mass certain sets of properties recur periodically 0 Put elements with similar properties in same column 0 Atomic Mass 0 Not all atoms of an element have the same mass l isotopes Q We generally use the average mass of all an element s atoms found in a sample in calculations l The average must take into account the abundance of each isotope in the sample 0 average mass is the atomic mass 0 calculation 21 0 Chemical packages Moles O Mole number of particles equal to the number of atoms in 12 g of C12 l 1 atom of C12 weighs exactly 12 amu l 1 mole of C12 weighs exactly 12g 0 number of particles in 1 mole is called avogadro s number 0 counting atoms by moles I If we can find the mass of a particular number of atoms we can use this information to convert the mass of an element sample into the number of atoms in the sample I 6022 10quot23 I calc 22 0 Relationship bw moles and mass l The mass of one mole of atoms is called the molar mass l The molar mass of an element in grams is numerically equal to the element s atomic mass in amu l calc 23 Chapter 3 Molecules Compounds and Chemical Equations 0 Elements and Compounds 0 Elements combine together to make an almost limitless number of compounds 0 The properties of the compound are totally different from the constituent elements 0 Chemical Bonds 0 Compounds are made of atoms held together by bonds 0 Chemical Bonds attractiveness between the electrons and the nucleus 0 The bonding attraction comes from attractions between protons and electrons 0 Bond Types 0 Two general bonding between atoms found in compounds ionic and covalent O ionic bonds complete transfer of electrons from one atom to another atom resulting in oppositely charged atoms that attract each other I generally found when metal atoms bond to nonmetal atoms 0 covalent sharing of electrons between two atoms I generally found when nonmetals bond together 0 Ionic compounds combination of cations and anions l formula is always the same as the empirical formula I sum of the charges on the cation and anion in each formula unit must qual zero 0 Formulas Describe Compunds 0 Compound distinct substance that is composed of atoms of two or more elements described by the number and type of each atom in the simplest unit chemical formula 0 Molecular View of Elements and Compounds 0 Pure substances l Elements 0 Atomic Ne 0 Molecular 02 l Compounds 0 Molecular H20 0 Ionic NaCl 0 Ionic vs Molecular Compounds l Molecular Compound 0 made of covalent bonds l Ionic Compound 0 made of ionic bond 0 Naming Compounds 0 Specific rules allow for systematic naming of materials to avoid confusion O Naming Monatomic Nonmetal Anion l Determine the charge from position on the Periodic table I To name anion change ending on the element name to ide O Ionic Compounds l metal stays the same ending of nonmetal changed to ide l Transition metal ionic compounds 0 Some metals can have different charge states 0 indicate charge on metal with Roman numerals 0 Molecular compounds I element further left in periodic table is fst l element closes to bottom of group is fst I if more than one compound can be formed from the same elements use prefixes to indicate number of each kind of atom l mono di tri tetra penta hexa hepta octa nona deca I first item doesn t use mono if it is single Molar Mass the sum of the atomic masses in a molecule 0 molecular mass amu molar mass gramsmol O Molar mass of compounds I relative masses of molecules can be calculated from atomic masses 0 see calc 31 Chapter 4 Chemical Quantities and Aqueous Reactions Quantities in Chemical Reactions 0 Uses stoichiometry and the mole method to calculate how much materials are used or produced by knowing information about the reaction I 1 Write a balanced chemical equation I 2 Convert quantities of known substances into moles l 3 Use coefficients in balanced equation to calculate the number of moles of the sought quantity l 4 Convert moles into desired units 0 The coefficients in a balanced chemical equation specify the relative amounts in moles of the substances involved in the reaction Predicting Amounts from Stoichiometry O The amounts of any other substance in a chemical reaction can be determined from the amount of just one substance 0 mass compound A gt Moles compound A gt Moles of Compound B gt Mass of compound B Limiting Reactant reagent that is used up first in a reaction Reaction Yield 0 Theoretical Yield amount of product that would result if all the limiting reagent reacted 0 Actual Yield amount of product actually obtained from a reaction 0 o Yield Actual YieldTheoretical Yield 100 Solutions homogenous mixture of 2 or more substances 0 solute substances present in the smaller amount 0 solvent the substance resent in the larger amount 0 Solution Concentration O quantitatively solutions are often described as dilute or concentrated l Dilute Small amounts of Solute l Concentrated Large amounts of Solute 0 concentration amount of solute in solvent in the form of molarity M amount of solute moles amount of solution in L Q Dilution procedure for preparing a less concentrated solution from a more concentrated solution add solvent 0 M1V1M2V2 V in L M in M 0 Solution Stoichiometry 0 Because molarity relates the moles of solute to the liters of solution it can be used to convert between amount of reactants andor products in a chemical reaction 0 Volume A gt Amount Amoles gt Amount Bmoles gt Volume B Q What Happens when a solute dissolves Q There are attractive forces between the solute particles holding them together 0 There are also attractive forces between the solvent molecules 0 When we mix the solute with the solvent there are attractive forces between the solute particles and the solvent molecules Q If the attractions between solute and solvent are strong enough the solute will dissolve Q Electrolytes and Nonelectrolytes 0 Materials that dissolve in water to form a solution that will conduct electricity are called electrolytes 0 Materials that dissolve in water to form a solution that will not conduct electricity are called nonelectrolytes 0 Salt vs Sugar dissolved in water 0 hydration process in which an ion is surrounded by water molecules arranged in a specific manner 0 lonic equations 0 Molecular equations describe the chemicals put inot the water and the product molecules 0 complete ionic equations describe the material s structure when dissolved l aqueous strong electrolytes written as ions 0 soluble salts strong acids strong bases l insoluble substances weak electrolytes and nonelectrolytes are written in molecule form 0 solids liquids gases 0 Acids and Bases O Arrhenius acid substance that produces H H30 in water 0 Arrhenius base substance that produces OH in water O Bronsted acid proton donor 0 Bronsted base proton acceptor O Monoprotic acid I Strong electrolyte strong acid I Weak electrolyte weak acid 0 diprotic acid I Strong electrolyte strong acid I weak electrolyte weak acid 0 Neutralization Reaction 0 acid base gt salt water 0 Acidbase titrations O titration solution of accurately known concentration is added gradually to another solution of unknown concentration until the chemical reaction between the two solutions is complete 0 Redox Reactions electron transfer reactions one element is oxidized one is reduced oxidation loses electron reduction gains electron 0000 Chapter 5 Gases Q The structure of a Gas 0 Gases are composed of particles that are flying around very fast in their container 0 The particles in straight lined until they encounter either the container wall or another particle then they bounce off 0 As they move and strike a surface they push on that surface I pressure forcearea 0 Physical characteristics of gases 0 Gases assume the volume and shape of their containers 0 Gases are the most compressible state of matter 0 Gases will mix evenly and completely when confined to the same container 0 Gases have much lower densities Q The pressure of a Gas 0 several factors I number of gas particles in a given volume I volume of the container l average speed of the gas particles 0 increasing altitude decreases pressure 0 ideal gas law PV nRT O P pressure V volume R gas constant T temperature 0 O O O n number of moles Molar volume volume of 1 mole of gas at STP Kinetic Molecular Theory 0 A gas is composed of molecules that are separated from each other by distances far greater than their own dimensions 0 Gas molecules are in constant motion in random directions 0 Gas molecules exert neither attractive nor repulsive forces on one another 0 The average kinetic energy of the molecules is proportional to the tempereature of the gas in kelvin Q There is a lot of empty space between gas particles 0 The average kinetic energy of the gas particles is directly proportional to the Kelvin temperature I as you raise the temp of the gas the speed of the particles increases Kinetic Energy and Molecular Velocities 0 Average kinetic energy of the gas molecules depends on the average mass and velocity I KE 12 mvquot2 O Gases in the same container have the same temp have same kinetic energy Real gas behavior 0 real molecules take up space the molar volume of a gas is larger than predicted by the ideal gas law at high pressures 0 real molecules attract each other the molar volume of a gas is smaller than predicted by the ideal gas law at low temperatures van der Waals equation 0 combining the equations to account for molecular attractions we get the following equation Chapter 14 Chemical Equilibrium Reaction Dynamics 0 When a reaction starts the reactants are consumed and products are made I forward reaction reactants gt products I reactant concentrations decrease and product concentrations increase I as reactant concentration decreases the forward rate decreases Arrow conventions 0 single arrow indicates all the reactant molecules are converted to product molecules at the end 0 double arrow indicates the reaction stops when only some of the reactant molecules have been converted into products equilibrium a state where there are no observable changes as time goes by chemical equilibrium O the rates of the forward and reverse reactions are equal 0 he concentrations of the reactants and products remain constant 0 Equilibrium constant 0 A relationship between the products and reactants exists at equilibrium based upon concentration known as the law of mass action 0 K productsreactants some value at some temperature 0 Homogenous Equilibrium reactions in which all reacting species are in the same phase 0 Heterogenous Equilibrium reactions in which reactants and products are in seperate phases 0 Writing Equilibrium Constant Expressions O In condensed species concentration expressed in M in gaseous phase concetration expressed in M or atm O The concentrations of pure solids pure liquids and solvents do not appear in equilibrium constant expressions 0 equilibrium constant is a dimensionless quantity 0 must specify balanced equation and the temperature Q If reaction expressed as sum of two or more reactions equilibrium constant is given by product of equilibrium constants of the individual reactions 0 Reaction Quotient calculated by substituting the initial concentrations into the equilibrium constant expression 0 When QgtK system moves from right to left 0 When QK system is at equilibrium 0 When QltK system moves from left to right 0 Approximations to Simplify the math 0 when equilibrium constant is very small position favors reactants O for large concentrations of reactants reactant concentration will not change significantly 0 Le Chatelier s Principle If a system at equilibrium is disturbed the position of equlibrium will shift to minimize the disturbance 0 Effect of concentration I product increase shift left I product decrease shift right I reactant increase shift right I reactant decrease shift left 0 Effect of pressure I pressure increase shift to side with fewest moles l pressure decrease shift to side with most moles l volume increase shift to side with most moles l volume decrease shift to side with fewest moles 0 Effect of temperature I in exothermic reaction heat is a product so increasing temperature is like adding heat shifting equilibrium away from heat 0 heat increase increase reactant concentrations decrease product concentration decreasing K I in endothermic reaction heat is a reactant 0 adding heat increases product concentrations and decreases reactant concentrations increasing K value I 0 Le Chatelier s Principle summary 0 Change Shift Equilibrium Chanqe Equilibrium M concentration yes no pressure yes no volume yes no temperature yes yes catalyst no no