Chem Final PDF

Chapter 10 10.1-IMF Forces ○ Ion-ion Between metal and nonmetal (KCl) Larger charge, greater attraction, this matters the most The smaller the radius, the greater the attraction Between two ionic compound...

Chapter 10 10.1-IMF Forces ○ Ion-ion Between metal and nonmetal (KCl) Larger charge, greater attraction, this matters the most The smaller the radius, the greater the attraction Between two ionic compounds ○ Ion-Dipole Attraction of an ion for a polar molecule One polar and one ionic component (NaCl + H20) ○ Dipole-dipole Attraction of the positive end of a molecule to the negative end of another molecule (H20) LIKE DISSOLVES LIKE (polar+polar)(nonpolar+nonpolar) POLAR ○ Higher boiling point, higher melting point ○ Dipole-Induced Dipole Attraction of polar molecule for non-polar molecule (CCl4+H20) ○ Induced Dipole/Induced Dipole- aka LD Attraction of nonpolar molecules over time (Everything) ○ H-Bonds Attraction between atoms in X-H bond F,O,N-Fluorine, Oxygen, Nitrogen ○ Polarization-Process of inducing a dipole Largest surface area, more polarizable ○ Polarizability-Degree to which the electron cloud of atom can be distorted to induce dipole 10.2-Liquid State ○ Surface Tension-Energy required to break through surface or disrupt a liquid drop and spread out the material ○ Capillary action-The rise of water in a small glass tube ○ Adhesive forces-The attractive forces between two types of molecules ○ Cohesive forces-The attractive forces between two molecules of some kind ○ Viscosity-Resistance to flow High viscosity=high IMF Type Examples Structural Units Forces Holding Units Ionic NaCl Positive+Negative ion-ion K2SO4 ions  NH4NO3 Metallic Iron Metal atoms, positive Metallic Copper metal ions with Brass delocalized valence electrons Polar Molecular H20 Molecule Dipole-Dipole, C6H10O6 H-Bonds, LD Nonpolar Molecular H2CO2 Molecule LD CH4 Network Graphite Atoms are held Covalent Bonds Diamond together in a 2D or Quartz 3D network Amorphous Glass Covalently bonded Nylon but with no long Polyethylene range regularity 10.4-Structure and Bonding in Metals ○ Band Model (Molecular orbital model)-The electrons in metallic bonding are assumed to travel around the metal crystal in molecular orbits formed from valence atomic orbitals of metal atoms ○ Alloy-Substance that contains a mixture of elements that has metallic properties (Bronze) ○ Substitutional ally-Some of the host atoms are replaced by atoms of a similar size ○ Interstitial alloy-Some of the holes in the closest packed atoms are occupied by small atoms 10.5-Carbon and Silicon: Network Atomic Solids ○ Network Solids-Diamond, Graphite, Quartz Atomic solids that contain strong covalent bonds to form a solid that might be viewed as a giant molecule ○ Silica-SiO2 Sand Glass-Silica heated above melting point and cooled quickly Quartz ○ Ceramics-Made of clays that contain silicates and are hardened at high temps ○ Semiconductor-Substance that does not conduct as well as a metal, but better than a non-metal 10.6-Molecular Solids ○ Molecular Solids-Solids that contain molecules at network sites instead of atoms  Ice, Dry ice 10.7 Ionic Solids ○ The structure of ions compounds are close-packed spheres of the larger ion with smaller ions in the holes\ 12.1-Reaction Rates ○ Chemical Kinetics-study of the rates of chemical reactions ○ Rate of a chemical reaction-Change in the concentration of a substance per change of time ○ Factors that affect rate Concentration Temperature Catalysts/Inhibitors Particle size 12.3 Determining the Form of the Rate Law ○ Rate of reaction rate=k[N2O5] ○ Rate constant-k-a number that relates to the rate of concentration ○ Fro the RXN aA+bB->xX The rate will be of the form: Rate=k[A]m[B]n ○ Order-the exponent of the concentration terms in the rate law 12.4 The Integrated Rate Law ○ 1st Order rate=k[A] ln[A] vs Time on graph ○ Second order rate=k[A]2 1/[A] vs Time on graph ○ Zero order rate=k [A] vs Time on graph ○ Half life-time required for concentration to decrease to half original value t1/2=.693/k 12.5 Reaction Mechanisms ○ Detailed pathway taken by atoms and molecules as rxn proceeds ○ Elementary step-Reaction whos rate can be written from its molecularity ○ Unimolecular Step-Rxn involving one molecule ○ Bimolecular Step-Rxn involving two molecules ○ Termolecular Step-Rxn involving three molecules Elementary Step Molecularity Rate Law A->Products Uni rate=k[A] A+A->Products Bi rate=k[A]2 A+B->Products Bi rate=k[A][B] A+A+B->Products Ter rate=k[A]2[B] A+B+C->Products Ter rate=k[A][B][C] Rxn mechanism ○ Series of elementary steps that satisfy 2 requirements Sum of elementary steps must give overall balanced equation Mechanism must agree with experimentally determined rate law SLOW STEP DETERMINES RATE Catalyst-Appears in reactants early step, products later step 12.6 A model for Chemistry Kinetics ○ Collision theory-theory that for a reaction to occur The reacting molecules must collide They must collide with sufficient energy They must collide in an orientation that can lead to the formation of atoms ○ Activation energy-(Ea)-energy barrier that must be overcome for the reaction to occur ○ Transition state-The arrangement of reactants and products molecules and atoms at the maximum point in the reaction 12.7 Catalysis ○ Catalyst-A substance that speeds up the reaction without being consumed itself ○ Enzyme-A biological catalyst that is very large, usually a protein, and speeds up the reaction by manipulating orientation 13.1 The Equilibrium Condition  ○ Equilibrium- A state in which the forward and reverse reactions occur at equal rate but no net change is observed 13.2 The Equilibrium Constant ○ Reaction Quotient- Q=[C]C[D]D/[A]A[B]B At any condition ○ When Reaction is at equilibrium K=[C]C[D]D/[A]A[B]B At equilibrium K has no units ○ Equilibrium Constant Expression Products are always in numerator Reactants in denominator Powers are stoichiometric coefficients K depends on the particular reaction and temperature Solids and liquids are omitted from equilibrium expression Pressure is used to find KP Concentration is used to find K 13.3 Equilibrium Expressions Involving Pressure ○ When using Kp, insert pressure instead of concentration 13.4 Heterogenous Equilibria ○ Homogeneous Equilibria-All reactants and products are in some phase ○ Heterogenous Equilibria-Reactants and products are in multiple phases Le Chatelier’s Principle Disturbance Change as Mixture Effect on Equilibrium Effect on K returns to Equilibrium Rise in Temperature Heat is consumed Shift in endothermic Change direction Drop in Temperature Released heat Shift in exothermic Change direction Addition of reactant Some reactants will Products increase, No change be consumed shift right Addition of product Some products will Reactants increase, No change be consumed shift left Decrease in volume, Shift to decrease Favor the side with No change increase in pressure pressure fewer moles Increase in volume, Shift to increase Favor the side with No change decrease in pressure pressure more moles 14.1 The natures of acids and bases  ○ Strong and weak electrolytes H+is just a porton, in water will always be H3O Strong acid ionizes completely to produce hydronium ions ○ Ionization constants-A measure of the extent substances ionize in water Stronger acids and bases K>>1 Weaker acids K1.0*10-7 In basic, [OH]>1.0*10-7 ○ At 25 C, 14=pH+pOH 14.4 Calculating pH of strong acids solution  ○ For a strong acid, you can do -log right away ○ Weak acid depends on Ka PERCENT IONIZATION ○ (x/y)*100 x=change from ICE chart y=initial condition 14.8 Acid-Base Properties of Salts ○ Salts with ions from a strong base and strong acid are neutral ○ Salts with ions from strong base and weak acid are basic, and vice versa LAST YEAR STUFF 5.1 Pressure Pressure-Force per unit area Millimeters of mercury-Unit of pressure also called a torr Standard atmospheres- A unit of pressure where 1 atm=760 mmHg Pascal-The SI unit of pressure, 1 N/m2 1 atm=760 mmHg=101.325kPa=1.01325 bar=14.7psi=101325Pa P1V1=P2V2 V1/T1=V2/T2 P1V1/T1=P2V2/T2 PV=nRT ○ R=.08206 6.1 Nature of Energy Thermodynamics-Science of Heat and work Energy-Capacity to do work Kinetic energy-energy of motion Thermal energy-Atom, ion, and molecule motion Mechanical energy-Large object motion Electric energy-Electron motion Sound-Expansion and compression of spaces between molecules First Law of Thermodynamics-Total energy in universe is constant(law of conservation of energy) Exothermic-HEat transfer from system to surroundings ○ Ex: Surroundings get warmer in Chem reaction Endothermic-HEat transfer from surroundings to system ○ Ex: Surroundings get colder in Chem reaction q=mcΔT ○ q=heat in joules ○ m=mass in grams ○ c=specific heat(J/g degrees celsius)  ΔT=Tf-Ti ○ Tf=Final temperature ○ Ti=Initial temperature Heat of fusion-Energy required to melt one gram of a substance at its melting point ○ Water=333 J/g Heat of vaporization-Energy to boil 1 gram of a substance at its boiling point ○ Water=2256 J/g Sublimation-water goes directly to gas Internal energy-Sum of chemical potential energy and kinetic energy within atoms, ions, and molecules ΔE=q+w ΔT Q solution-mcΔT Q reaction- opposite of q solution Moles limiting reactant ΔH- qrxn/mol LR 7.1 Electromagnetic Radiation Electomagnetic radiation-Light waves, rays, radio waves, microwaves, visible light, UV light, gamma rays, x-rays Wavelength-(λ) Distance between successive crests of a wave Frequency (V) number of waves that pass by in a given amount of time Amplitude-Maximum height of the wave Nodes-Places of zero amplitude Speed-Wavelength times frequency ○ C=λ x V ○ C is the speed of light ○ C=2.99792458x10^8 m/s Energy=Planck’s constant(6.626x10^-34) times frequency Spdf notation-1s, 2s, 2p, 3s, 3p, 3d, 4s, 4p, 4d, 4f