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AP Chemistry Flashcards

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13722069404atomic numbernumber of electrons/protons in the atom0
13722069405molar massaverage mass of a single atom measured in amus; also the average mass for one mole of the atom in grams1
13722069406periodshorizontal rows2
13722069407groupsvertical rows3
13722069408alkali metalsG1 elements4
13722069409alkaline earth metalsG2 elements5
13722069410transition metalsG3 through G126
13722069411halogensG177
13722069412noble gasesG188
13722069413lanthanides and actinidesrare earth elements; inner transition metals9
13722069414protonpositively charged particle in the nucleus; # of which determines the properties of an element10
13722069415neutronneutral particles in the nucleus of an atom11
13722069416electronsmall, negatively charged particle surrounding an atom in orbitals12
13722069417mass numbersum of protons and neutrons13
13722069418isotopeelement with a different number of neutrons14
13722069419mass spectrometrymass of various isotopic elements to create a mass spectrum graph15
13722069420moleunit used to represent large numbers of small particles such as atoms, molecules, electrons, or ions16
13722069421avogadros number6.022 E2317
13722069422ideal gas lawpv=nrt18
13722069423? L/mol22.4 L19
13722069424percent compositionpercent by mass of each element that makes up a compound; mass part/mass whole20
13722069425empirical formulasimplest ratio of the molecules making up a compound21
13722069426molecular formulaactual formula for a substance22
13722069427aufbau principlee- are placed in orbitals, subshells, and shells in order of increasing energy23
13722069428quantizede- can only exist at specific energy levels separated by specific intervals24
13722069429pauli exclusion principletwo electrons who share an orbital cannot have the same spin (must be clockwise and counterclockwise); magnetic moment25
13722069430hunds rulewhen an electron is added to a subshell it will always occupy an empty orbital if one is available26
13722069431coulombs lawthe amount of energy that an electron has depends on its distance from the nucleus of an atom; e=k(q1*q20)/r27
13722069432quantum theoryelectromagnetic energy is quantized; for a given frequency of light or radiation, all possible energies are multiples of a certain unit (a quantum)28
13722069433quantum energy equatione=hv29
13722069434bohr modeleach energy level is represented by a row in the periodic table30
13722069435electromagnetic radiationthe form in which atoms absorb energy31
13722069436when electron drops to a lower energy levelthen electromagnetic radiation is released (energy)32
13722069437frequency and wavelength areinversely proportional; c=hv33
13722069438ionization energyamount of energy necessary to remove electrons from an atom (electromagnetic energy exceeds binding energy)34
13722069439unit for binding energykj/mol or Mj/mol35
13722069440kinetic energyenergy of motion36
13722069441photoelectron spectra (pes)charted amounts of ionizations energies for electrons ejected from a nucleus; can be used to identify elements37
13722069442ionan atom which has either gained or lost electrons38
13722069443anionparticle with more electrons than protons; negatively charged39
13722069444cationparticle with less electrons than protons; positively charged40
13722069445daltonmodern atomic theory; elements combined in different ratios; are never created nor destroyed in chemical reactions41
13722069446mendeleev & meyerindependent proposals of early periodic tables42
13722069447thomsons experimentcathode ray tube; deflection of charges that concluded atoms are composed of positive and negative particles43
13722069638plum pudding model44
13722069448millikans experimentcalculated charge on an electron by examining the behavior of charged oil drops in an electric field45
13722069449rutherfords experimentfired alpha particles at gold foil and observed how they scattered; concluded that all of the positive charge was concentrated in the center and that an atom is mostly empty space46
13722069450heisenberg uncertainty principleit is impossible to know both the position and momentum of an electron at a particular instant; means electron orbitals do NOT represent specific orbits47
13722069451shielding electronselectrons between a valence electron and the nucleus that decreases the attraction between the nucleus and the valence electron48
13722069452stable atoms have... completed shells49
13722069639metalloids50
13722069453atomic radiusapproximate distance from the nucleus of an atom to its valence electrons51
13722069454periodic trend: left to rightperiodic trend: atomic radius decreases; protons are added to the nucleus so valence electrons are more strongly attracted ionization energy increases (protons are added to the nucleus)52
13722069455periodic trend: down a groupperiodic trend: atomic radius increases; shells of electrons are added which shield the more distant shells and valence e- get farther away ionization energy decreases (shells of e- added, each inner shell shields more and reduces the pull on valence e- so they are easier to remove)53
13722069456periodic trend: cationsperiodic trend: ... are smaller than atoms; e- is removed and a shell is lost and electron-electron repulsions are reduced54
13722069457periodic trend: anionsperiodic trend: ... are larger than atoms; e- is added, electron-electron repulsions increase and valence electrons move farther apart55
13722069458ionization energy magnitudessubsequent energies are larger because the e-e repulsion decreases and the remaining valence e- are closer to the nucleus; once a shell is empty the energy required to remove an e- from a full shell is significantly greater than previous energies56
13722069459electronegativityhow strongly the nucleus of an atom attracts the electrons of other atoms in a bond57
13722069460factors that affect electronegativitysmaller atom; greater EN closer the element is to having a full energy level; higher EN58
13722069461EN trendsleft to right; EN increases down a group; EN decreases59
13722069462bondingtransfer or sharing of electrons60
13722069463ionic solidcompound held together by electrostatic attractions that are in a lattice structure; weak conductors (e- are localized around a single atom); no IMFs61
13722069464ionic bondbond between metal and nonmetal; electrons are NOT shared: the cation gives an e- up to the anion62
13722069465properties of ionic solidsare solid at room temperature; high melting and boiling points63
137220694662 factors that affect melting points in ionic substancesprimary factor: charge on the ions (greater charges, greater Coulombic attraction) secondary factor: smaller atoms (greater Coulombic attraction)64
13722069467salts have __________ bondingionic bonding65
13722069468metallic bondingbond between two metals; sea of electrons that make metals such good conductors; delocalized structure allows for malleability and ductility66
13722069469interstitial alloymetal atoms with vastly different radii combine; ex. steel67
13722069470substitutional alloymetal atoms with similar radii combine; ex. brass68
13722069471covalent bondsbond in which two atoms share electrons; each atom counts the e- as a part of its valence shell69
13722069472single bondsone sigma bond, one e- pair; longest bond, least energy70
13722069473double bondsone sigma bond, one pi bond; two e- pairs71
13722069474triple bondsone sigma bond, two pi bonds; 3 e- pairs; shortest bond, most energy72
13722069475network covalent bondslattice of covalent bonds; network solid (acts similar to one molecule); very hard, high melting/boiling points; poor conductors73
13722069476the common network solidsSiO2,74
13722069477dopingthe addition of an impurity to an existing lattice75
13722069478p-dopingcreate a hole (positively charged) that draws electrons through the substance (add a substance with one LESS valence e-) i.e. si + al76
13722069479n-dopingadd a substance with one MORE valence e- which leaves a free e- to travel freely i.e. si + p77
13722069480polarityexists when a molecule has a clustering of negative charge on one side due to unequal sharing of electrons (e- are pulled to the more electronegative side); creates dipoles in molecules78
13722069481dipole momentthe measurement of the polarity of a molecule; the unit of measurement is a debye (D)79
13722069482more polar molecule........ larger dipole moment80
13722069483intermolecular forces (IMFs)forces that exist between molecules in a covalently bonded substance; not bonds81
13722069484dipole-dipole forcesthe positive end of one polar molecule is attracted to the negative end of another molecule; relatively weak attraction force82
13722069485hydrogen bondingstrong IMF between two moelcules; F, O, N; have higher melting and boiling points than molecules with other IMFs83
13722069486london dispersion forcesIMFs that occur between all molecules; occur because of the random motions of electrons on atoms within molecules to create instantaneous polarities; molecules with more e- will have greater _________________ forces84
13722069487substances with only london dispersion forces usually...... are gases at room temp, and boil/melt at extremely low temps85
13722069488melting & boiling points of a covalent substance is almost always _____________ than that of ionic substanceslower86
13722069489vapor pressurethe pressure exerted by a vapor over a liquid87
13722069490vaporizationthe process by which molecules with enough KE inside a liquid break the surface of the liquid and transition into the gaseous phase; no outside energy is needed i.e. no heating88
13722069491vapor pressure is primarily dependent ondependent on IMFs89
13722069492resonance structuresstructures that occur when it is possible to draw two or more valid lewis electron dot diagrams that have the same number of electron pairs for a molecule or ion90
13722069493formal chargeused to find which structure is most likely to occur; valence - assigned91
13722069494assigned e-lone pairs of e- count as two and bonds count as one92
13722069495valence shell electron-pair repulsion model (VSEPR)model used to predict molecular geometry based on the principle that electrons repel each other and therefore are as far apart as possible in a structure93
13722069496hybrid orbitalsorbitals that have the properties to explain the geometry of bonds between atoms94
13722069497linear geometrysp hybridization 0 lone pairs ex. BeCl2 & CO295
13722069498trigonal planar geometrysp2 hybridization bond angles 120 0 lone pairs: trigonal planar (three bonds) 1 lone pair: bent (two bonds)96
13722069499tetrahedral geometry4 e- pairs, sp3 hybridization angles 109.5 0 lone pairs: tetrahedral (four bonds) [CH4, NH4+, ClO4-, SO4 2-, PO4 3-] 1 lone pair: trigonal pyramidal (3 bonds) [NH3, PCl3, SO3 2-] 2 lone pairs: bent (2 bonds) [H2O, OF2, NH2-]97
13722069500trigonal bipyramidal geometry5 e- pairs, sp4 hybridization 0 lone pairs: trigonal bipyramidal (5 bonds) [PCl5, PF5] 1 lone pair: seesaw (4 bonds) [SF4, IF4+] 2 lone pairs: t-shaped (3 bonds) [ClF3, ICl3] 3 lone pairs: linear (2 bonds) [XeF2, I3-]98
13722069501octahedral geometry6 e- pairs, sp5 hybridization 0 lone pairs: octahedral (6 bonds) [SF6] 1 lone pair: square pyramidal (5 bonds) [BrF5, IF5] 2 lone pairs: square planar (4 bonds) [XeF4]99
13722069502kinetic molecular theorythe theory that all matter is composed of particles (atoms and molecules) moving constantly in random directions100
13722069503KE=0.5mv^2average kinetic energy of a single gas molecule (ideal gas)101
13722069504ideal gas(gas) high temperature, low pressure, no attractive forces, in constant motion without losing energy102
13722069505maxwell-boltzmann diagramsshows the range of velocities for molecules of a gas103
13722069506effusionthe rate at which a gas will escape from a container through microscopic holes in the surface of the container104
13722069507factors that affect rate of effusionspeed of gas molecules (so ________ increases with higher temperature and lower mass)105
13722069508combined gas law(P1*V1)/T1=(P2*V2)/T2106
13722069509boyles lawif temperature is constant: as pressure increases, volume decreases as volume increases, pressure decreases107
13722069510charles lawif pressure is constant: as temp increases, volume increases108
13722069511if volume is constant:as pressure increases, temperature increases109
13722069512daltons lawthe total pressure of a mixture of gases is just the sum of all the partial pressures of the individual gases in the mixture110
13722069513partial pressurethe pressure of each gas in a mixture; is directly proportional to the number of moles of gas in the mixture Pa = (Ptotal) (moles of A/total moles)111
13722069514molaritythe concentration of a solution in terms of moles of solution/volume (L)112
13722069515mole fractionmoles of substance/total moles in solution113
13722069516solutesubstance being dissolved114
13722069517solventa liquid substance capable of dissolving other substances115
13722069518dissociationwhen ionic substances break up into ions into solution116
13722069519electrolytesfree ions in solution that conduct electricity117
13722069520paper chromatographythe separation of a mixture by passing it through a medium in which the components of the solution move at different rates118
13722069521retention factorstronger the attraction between the solute and the solvent front is, the larger the Rf value will be119
13722069522column chromatographya column is packed with stationary substance, then the solution to be separated (analyte) is injected into the column where it adheres to the stationary phase, then the eluent solution is injected into the column. as the eluent solution passes through the stationary phase the analyte molecules will be attracted to it with varying degrees of strength based on polarity120
13722069523distillationthe process that separates the substances in a solution based on their boiling points121
13722069524saltan ionic compound made from the neutralization of an acid with a base122
13722069525synthesis reactionwhen elements or simple compounds are combined to form a single, more complex compound123
13722069526decomposition reactiona reaction where a single compound os split into two or more elements or simple compounds, usually in the presence of heat; opposite of a synthesis124
13722069527acid-base reactiona reaction when an acid reacts with a base to form water and a salt125
13722069528oxidation-reduction reactiona reaction that results in the change of the oxidation states of some participating species126
13722069529hydrocarbon combustionhydrocarbon + oxygen --> carbon dioxide + water a substance is ignited (usually a hydrocarbon) and it reacts with oxygen in the atmosphere; products are always CO2 and H2O127
13722069530precipitation reactiona reaction in which an insoluble substance (salt) forms and separates from the solution128
13722069531net ionic equationan equation for a reaction in solution showing only those particles that are directly involved in the chemical change129
13722069532limiting reactantthe substance that controls the quantity of product that can form in a chemical reaction; moles of each reactant divided by moles used in reaction130
13722069533hydrocarbonan organic compound composed only of carbon and hydrogen131
13722069534law of conservation of massmatter can be neither created nor destroyed during a chemical reaction132
13722069535gravimetric analysisa type of quantitative analysis in which the amount of a species in a material is determined by converting the species to a precipitate that can be isolated completely and weighed133
13722069536when bonds are formed...energy is released134
13722069537when bonds are broken...energy is absorbed135
13722069538exothermicproducts have stronger bonds than the reactants; heat is released, - ΔH136
13722069539endothermicreactants have stronger bonds than the products; heat is absorbed, + ΔH137
13722069540activation energythe minimum amount of energy required to start a chemical reaction138
13722069541catalystsubstance that speeds up a reaction by reducing the activation energy required by the reaction; provides an alternate reaction pathway; no effect on equilibrium conditions139
13722069542oxidation number: H+1140
13722069543oxidation number: alkali metals+1141
13722069544oxidation number: alkaline earth metals+2142
13722069545oxidation number: oxygen-2143
13722069546oxidation number: halogens-1144
13722069547hydroxideOH-145
13722069548nitrateNO3-146
13722069549acetateC2H3O2-147
13722069550cyanideCN-148
13722069551permanganateMnO4-149
13722069552carbonateCO3 2-150
13722069553sulfateSO4 2-151
13722069554dichromateCr2O7 2-152
13722069555phosphatePO4 3-153
13722069556ammoniumNH4+154
13722069557half-reactionsthe two parts of an oxidation-reduction reaction, one representing oxidation, the other reduction155
13722069558titrationthe slow addition of a solution at a known concentration to another solution in order to determine the concentration of the unknown solution; color change is often used as an end point156
13722069559galvanic (voltaic) cella favored redox reaction in a cell is used to generate an electric current157
13722069560currentunit: amperes (amps); the flow of electrons from one place to another158
13722069561anodewhere oxidation takes place159
13722069562cathodewhere reduction takes place160
13722069563electrolyctic cellan outside source id used to force an unfavored redox rxn to take place161
13722069564purpose of a salt bridgemaintains electrical neutrality in the cell162
13722069565favored redox reaction+E163
13722069566unfavored redox reaction-E164
13722069567elecroplatinga process that uses electric current to reduce dissolved metal cations so that they form a thin metal coating on an electrode165
13722069568rate lawan expression relating the rate of a reaction to the concentration of the reactants166
13722069569first order rate lawy= ln[a] subscript (t) m= -k x= time b= ln[a] subscript (0)167
13722069570half-lifethe amount of time it takes for half of a sample to disappear; t1/2=0.693/k168
13722069571second order rate law[a] sub. (t) = concentration of reactant A at time (t) [a] sub. (0) = initial conc. of A k = rate constant t = time elapsed169
13722069572zero order rate lawsrate does not depend on the concentration of the reactants at all therefore rate is always the same at a given temperature; rate=k170
13722069573collision theorytheory that collisions occur because reactants are constantly moving around and colliding with one another171
13722069574effective collisionscollisions in which the conditions of the collision theory are met (and therefore the reaction occurs)172
13722069575ineffective collisionscollisions in which the conditions of the collision theory are not met (and therefore reaction does not occur)173
13722069576spectrophotometeran instrument that measures the proportions of light of different wavelengths absorbed and transmitted by a pigment solution174
13722069577beer's lawA=abc A=absorbance a=molar absorptivity b=path length; the distance the light is traveling through the solution c=concentration of the solution175
13722069578rate-determining stepthe slowest step in a reaction mechanism that determines the overall rate of the reaction176
13722069579elementary stepsa series of simple reactions that represent the progress of the overall reaction at the molecular level177
13722069580workforce exerted on an object that causes it to move178
13722069581first law of thermodynamicsthe energy of the universe is constant179
13722069582second law of thermodynamicsif a process is favored in one direction, then it cannot be favored in the reverse reaction; and an increase in entropy promotes favored reactions180
13722069583entropyΔS; a measure of the randomness or disorder of the system181
13722069584enthalpyΔH; heat of a system at constant pressure182
13722069585Gibbs free-energyΔG; a measure of whether or not a process will proceed without the input of outside energy ∆G=∆H-T∆S (T in degrees Kelvin) when ΔG=0, the reaction is at equilibrium183
13722069586state functionsfunctions that depend only on the change between the initial and final states of a system and therefore independent of the reaction pathway (catalyst has no effect) ΔS, ΔH, ΔG184
13722069587standard state conditionsall gases are 1 atm all liquids are pure all solids are pure all solutions are 1 molar the energy of formation of an element in its normal state is defined as zero the temperature used is 25C or 273K185
13722069588ΔH°f (heat of formation)the change in energy that takes place when one mole of a compound is formed from its pure components under STP186
13722069589STPstandard temp. and pressure187
13722069590bond energythe energy required to break a bond; endothermic process (add energy)188
13722069591hess's lawif a reaction can be described by a series of steps, then ΔH for the overall reaction is the sum of the ΔH values for all the steps189
13722069592rules of hess's law1. if you flip the equation, flip the sign on ΔH 2. if you multiply or divide an equation by a #, multiply ΔH by the same # 3. if several equations in summation create a new equation, you can also add the ΔH values of those component equations to get the ΔH value for the new equation190
13722069593enthalpy of solutionthe amount of energy released or absorbed as heat when a specific amount of solute dissolves in a solvent191
13722069594solid to liquidmelting192
13722069595liquid to solidfreezing193
13722069596liquid to gasvaporization194
13722069597gas to liquidcondensation195
13722069598solid to gassublimation196
13722069599gas to soliddeposition197
13722069600heat of fusionthe energy that must be absorbed by a solid to melt it198
13722069601heat of vaporizationthe energy that must be put into a liquid to turn it into a gas199
13722069640phase diagram (water)200
13722069602calorimetrythe measurement of heat changes during chemical reactions201
13722069603specific heatthe amount of heat required to the temperature of one gram of a substance by one degree celsius202
13722069604heating/cooling curvescurves that display what happens to the temperature of a substance as heat is added203
13722069605spontaneousthermodynamically favored; -ΔG204
13722069606nonspontaneousthermodynamically unfavored; +ΔG205
13722069607at low temperatureenthalpy is dominant; ΔH206
13722069608at high temperatureentropy is dominant; ΔS207
13722069609voltage vs favorabilitya redox reaction is favored if voltage is (+)208
13722069610hydration energythe energy required to break hydrogen bonds209
13722069611law of mass actionthe rate of a chemical reaction is proportional to the product of the concentrations of the reactants210
13722069612a solution is at equilibrium whenthe rate of the forward reaction is equal to the rate of the reverse reaction211
13722069613large k eq valueproducts are favored at equilibrium212
13722069614small k eq valuereactants are favored at equilibrium213
13722069615le chateliers principlestates that if a stress is applied to a system at equilibrium, the system shifts in the direction that relieves that stress214
13722069616reaction quotientQ215
13722069617Q > Kprecipitate forms; reaction shifts left216
13722069618Q < Kprecipitate does not form; reaction shifts right217
13722069619Q = Kthe reaction is at equilibrium; voltage in a voltaic cell reaches zero218
13722069620common ion effecta decrease in the solubility of an ionic compound caused by the addition of a common ion219
13722069621Arrhenius acidsa substance that ionizes in water and produces hydrogen ions220
13722069622Arrhenius basesa substance that ionizes in water and produces hydroxide ions221
13722069623Brønsted-Lowry acidsa substance that is capable of donating a proton222
13722069624Brønsted-Lowry basesa substance that is capable of accepting a proton223
13722069625pH-log [H+]224
13722069626pOH-log [OH-]225
13722069627pKa-log [Ka]226
13722069628pKb-log [Kb]227
13722069629amphoterica substance that can act as both an acid and a base; ex. H2O228
13722069630strong acidsdissociate completely in water; reaction goes to completion and never reaches equilibrium229
13722069631weak acidmost of the acid molecules remain in solution and very few dissociate230
13722069632percent dissociationthe ratio of the amount of a substance that is dissociated at equilibrium to the initial concentration of the substance in a solution, multiplied by 100231
13722069633oxoacidsacids that contain oxygen; the more oxygens, the stronger the acid232
13722069634polyprotic acidsacids that can donate more than one H+233
13722069635Kw1.0x10^-14234
13722069636henderson hasselbachpH = pKa + log([A-]/[HA])235
13722069637buffersweak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH236

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