fired 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 space
Back
electron
Front
small, negatively charged particle surrounding an atom in orbitals
Back
aufbau principle
Front
e- are placed in orbitals, subshells, and shells in order of increasing energy
Back
alkali metals
Front
G1 elements
Back
isotope
Front
element with a different number of neutrons
Back
molecular formula
Front
actual formula for a substance
Back
? L/mol
Front
22.4 L
Back
anion
Front
particle with more electrons than protons; negatively charged
Back
ideal gas law
Front
pv=nrt
Back
noble gases
Front
G18
Back
shielding electrons
Front
electrons between a valence electron and the nucleus that decreases the attraction between the nucleus and the valence electron
Back
transition metals
Front
G3 through G12
Back
thomsons experiment
Front
cathode ray tube; deflection of charges that concluded atoms are composed of positive and negative particles
Back
quantized
Front
e- can only exist at specific energy levels separated by specific intervals
Back
when electron drops to a lower energy level
Front
then electromagnetic radiation is released (energy)
Back
atomic number
Front
number of electrons/protons in the atom
Back
groups
Front
vertical rows
Back
periods
Front
horizontal rows
Back
cation
Front
particle with less electrons than protons; positively charged
Back
stable atoms have
Front
... completed shells
Back
dalton
Front
modern atomic theory; elements combined in different ratios; are never created nor destroyed in chemical reactions
Back
photoelectron spectra (pes)
Front
charted amounts of ionizations energies for electrons ejected from a nucleus; can be used to identify elements
Back
kinetic energy
Front
energy of motion
Back
quantum energy equation
Front
e=hv
Back
mass spectrometry
Front
mass of various isotopic elements to create a mass spectrum graph
Back
alkaline earth metals
Front
G2 elements
Back
frequency and wavelength are
Front
inversely proportional; c=hv
Back
unit for binding energy
Front
kj/mol or Mj/mol
Back
lanthanides and actinides
Front
rare earth elements; inner transition metals
Back
mass number
Front
sum of protons and neutrons
Back
molar mass
Front
average mass of a single atom measured in amus; also the average mass for one mole of the atom in grams
Back
electromagnetic radiation
Front
the form in which atoms absorb energy
Back
hunds rule
Front
when an electron is added to a subshell it will always occupy an empty orbital if one is available
Back
percent composition
Front
percent by mass of each element that makes up a compound; mass part/mass whole
Back
mendeleev & meyer
Front
independent proposals of early periodic tables
Back
proton
Front
positively charged particle in the nucleus; # of which determines the properties of an element
Back
bohr model
Front
each energy level is represented by a row in the periodic table
Back
plum pudding model
Front
Back
neutron
Front
neutral particles in the nucleus of an atom
Back
millikans experiment
Front
calculated charge on an electron by examining the behavior of charged oil drops in an electric field
Back
mole
Front
unit used to represent large numbers of small particles such as atoms, molecules, electrons, or ions
Back
avogadros number
Front
6.022 E23
Back
halogens
Front
G17
Back
pauli exclusion principle
Front
two electrons who share an orbital cannot have the same spin (must be clockwise and counterclockwise); magnetic moment
Back
ionization energy
Front
amount of energy necessary to remove electrons from an atom (electromagnetic energy exceeds binding energy)
Back
empirical formula
Front
simplest ratio of the molecules making up a compound
Back
coulombs law
Front
the amount of energy that an electron has depends on its distance from the nucleus of an atom; e=k(q1*q20)/r
Back
heisenberg uncertainty principle
Front
it is impossible to know both the position and momentum of an electron at a particular instant; means electron orbitals do NOT represent specific orbits
Back
quantum theory
Front
electromagnetic energy is quantized; for a given frequency of light or radiation, all possible energies are multiples of a certain unit (a quantum)
Back
Section 2
(50 cards)
periodic trend: cations
Front
periodic trend: ... are smaller than atoms; e- is removed and a shell is lost and electron-electron repulsions are reduced
Back
periodic trend: left to right
Front
periodic 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)
Back
intermolecular forces (IMFs)
Front
forces that exist between molecules in a covalently bonded substance; not bonds
Back
the common network solids
Front
SiO2,
Back
metallic bonding
Front
bond between two metals; sea of electrons that make metals such good conductors; delocalized structure allows for malleability and ductility
2 factors that affect melting points in ionic substances
Front
primary factor: charge on the ions (greater charges, greater Coulombic attraction)
secondary factor: smaller atoms (greater Coulombic attraction)
Back
formal charge
Front
used to find which structure is most likely to occur; valence - assigned
Back
substitutional alloy
Front
metal atoms with similar radii combine; ex. brass
Back
periodic trend: down a group
Front
periodic 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)
Back
london dispersion forces
Front
IMFs 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 _________________ forces
Back
n-doping
Front
add a substance with one MORE valence e- which leaves a free e- to travel freely
i.e. si + p
structures 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 ion
Back
ionic solid
Front
compound held together by electrostatic attractions that are in a lattice structure; weak conductors (e- are localized around a single atom); no IMFs
Back
EN trends
Front
left to right; EN increases
down a group; EN decreases
Back
polarity
Front
exists 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 molecules
Back
atomic radius
Front
approximate distance from the nucleus of an atom to its valence electrons
Back
valence shell electron-pair repulsion model (VSEPR)
Front
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 structure
Back
assigned e-
Front
lone pairs of e- count as two and bonds count as one
Back
properties of ionic solids
Front
are solid at room temperature; high melting and boiling points
Back
vaporization
Front
the 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 heating
Back
salts have __________ bonding
Front
ionic bonding
Back
melting & boiling points of a covalent substance is almost always _____________ than that of ionic substances
Front
lower
Back
dipole-dipole forces
Front
the positive end of one polar molecule is attracted to the negative end of another molecule; relatively weak attraction force
Back
double bonds
Front
one sigma bond, one pi bond; two e- pairs
Back
hydrogen bonding
Front
strong IMF between two moelcules; F, O, N; have higher melting and boiling points than molecules with other IMFs
Back
single bonds
Front
one sigma bond, one e- pair; longest bond, least energy
create a hole (positively charged) that draws electrons through the substance (add a substance with one LESS valence e-) i.e. si + al
Back
trigonal planar geometry
Front
sp2 hybridization
bond angles 120
0 lone pairs: trigonal planar (three bonds)
1 lone pair: bent (two bonds)
Back
electronegativity
Front
how strongly the nucleus of an atom attracts the electrons of other atoms in a bond
Back
bonding
Front
transfer or sharing of electrons
Back
hybrid orbitals
Front
orbitals that have the properties to explain the geometry of bonds between atoms
Back
network covalent bonds
Front
lattice of covalent bonds; network solid (acts similar to one molecule); very hard, high melting/boiling points; poor conductors
Back
triple bonds
Front
one sigma bond, two pi bonds; 3 e- pairs; shortest bond, most energy
Back
factors that affect electronegativity
Front
smaller atom; greater EN
closer the element is to having a full energy level; higher EN
Back
vapor pressure is primarily dependent on
Front
dependent on IMFs
Back
doping
Front
the addition of an impurity to an existing lattice
Back
substances with only london dispersion forces usually...
Front
... are gases at room temp, and boil/melt at extremely low temps
Back
covalent bonds
Front
bond in which two atoms share electrons; each atom counts the e- as a part of its valence shell
Back
vapor pressure
Front
the pressure exerted by a vapor over a liquid
Back
ionization energy magnitudes
Front
subsequent 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 energies
Back
more polar molecule....
Front
.... larger dipole moment
Back
ionic bond
Front
bond between metal and nonmetal; electrons are NOT shared: the cation gives an e- up to the anion
Back
metalloids
Front
Back
periodic trend: anions
Front
periodic trend: ... are larger than atoms; e- is added, electron-electron repulsions increase and valence electrons move farther apart
Back
dipole moment
Front
the measurement of the polarity of a molecule; the unit of measurement is a debye (D)
Back
interstitial alloy
Front
metal atoms with vastly different radii combine; ex. steel
Back
Section 3
(50 cards)
limiting reactant
Front
the substance that controls the quantity of product that can form in a chemical reaction; moles of each reactant divided by moles used in reaction
Back
acid-base reaction
Front
a reaction when an acid reacts with a base to form water and a salt
Back
hydroxide
Front
OH-
Back
acetate
Front
C2H3O2-
Back
precipitation reaction
Front
a reaction in which an insoluble substance (salt) forms and separates from the solution
Back
molarity
Front
the concentration of a solution in terms of moles of solution/volume (L)
Back
charles law
Front
if pressure is constant: as temp increases, volume increases
Back
hydrocarbon
Front
an organic compound composed only of carbon and hydrogen
Back
oxidation number: oxygen
Front
-2
Back
paper chromatography
Front
the separation of a mixture by passing it through a medium in which the components of the solution move at different rates
Back
cyanide
Front
CN-
Back
distillation
Front
the process that separates the substances in a solution based on their boiling points
Back
hydrocarbon combustion
Front
hydrocarbon + oxygen --> carbon dioxide + water
a substance is ignited (usually a hydrocarbon) and it reacts with oxygen in the atmosphere; products are always CO2 and H2O
Back
maxwell-boltzmann diagrams
Front
shows the range of velocities for molecules of a gas
Back
partial pressure
Front
the 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)
Back
exothermic
Front
products have stronger bonds than the reactants; heat is released, - ΔH
Back
factors that affect rate of effusion
Front
speed of gas molecules (so ________ increases with higher temperature and lower mass)
Back
dissociation
Front
when ionic substances break up into ions into solution
Back
kinetic molecular theory
Front
the theory that all matter is composed of particles (atoms and molecules) moving constantly in random directions
Back
oxidation number: H
Front
+1
Back
net ionic equation
Front
an equation for a reaction in solution showing only those particles that are directly involved in the chemical change
Back
oxidation number: alkaline earth metals
Front
+2
Back
effusion
Front
the rate at which a gas will escape from a container through microscopic holes in the surface of the container
Back
boyles law
Front
if temperature is constant: as pressure increases, volume decreases
as volume increases, pressure decreases
Back
nitrate
Front
NO3-
Back
endothermic
Front
reactants have stronger bonds than the products; heat is absorbed, + ΔH
Back
column chromatography
Front
a 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 polarity
Back
when bonds are formed
Front
...energy is released
Back
retention factor
Front
stronger the attraction between the solute and the solvent front is, the larger the Rf value will be
Back
solvent
Front
a liquid substance capable of dissolving other substances
Back
decomposition reaction
Front
a reaction where a single compound os split into two or more elements or simple compounds, usually in the presence of heat; opposite of a synthesis
Back
activation energy
Front
the minimum amount of energy required to start a chemical reaction
Back
when bonds are broken
Front
...energy is absorbed
Back
oxidation number: halogens
Front
-1
Back
synthesis reaction
Front
when elements or simple compounds are combined to form a single, more complex compound
Back
solute
Front
substance being dissolved
Back
salt
Front
an ionic compound made from the neutralization of an acid with a base
Back
electrolytes
Front
free ions in solution that conduct electricity
Back
gravimetric analysis
Front
a 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 weighed
Back
law of conservation of mass
Front
matter can be neither created nor destroyed during a chemical reaction
Back
daltons law
Front
the total pressure of a mixture of gases is just the sum of all the partial pressures of the individual gases in the mixture
Back
if volume is constant:
Front
as pressure increases, temperature increases
Back
oxidation number: alkali metals
Front
+1
Back
combined gas law
Front
(P1V1)/T1=(P2V2)/T2
Back
oxidation-reduction reaction
Front
a reaction that results in the change of the oxidation states of some participating species
Back
mole fraction
Front
moles of substance/total moles in solution
Back
ideal gas
Front
(gas) high temperature, low pressure, no attractive forces, in constant motion without losing energy
Back
KE=0.5mv^2
Front
average kinetic energy of a single gas molecule (ideal gas)
Back
permanganate
Front
MnO4-
Back
catalyst
Front
substance that speeds up a reaction by reducing the activation energy required by the reaction; provides an alternate reaction pathway; no effect on equilibrium conditions
Back
Section 4
(50 cards)
effective collisions
Front
collisions in which the conditions of the collision theory are met (and therefore the reaction occurs)
Back
STP
Front
standard temp. and pressure
Back
phosphate
Front
PO4 3-
Back
solid to gas
Front
sublimation
Back
electrolyctic cell
Front
an outside source id used to force an unfavored redox rxn to take place
Back
gas to liquid
Front
condensation
Back
titration
Front
the 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 point
Back
galvanic (voltaic) cell
Front
a favored redox reaction in a cell is used to generate an electric current
Back
collision theory
Front
theory that collisions occur because reactants are constantly moving around and colliding with one another
Back
Gibbs free-energy
Front
ΔG; 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 equilibrium
Back
standard state conditions
Front
all 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 273K
Back
unfavored redox reaction
Front
-E
Back
liquid to gas
Front
vaporization
Back
work
Front
force exerted on an object that causes it to move
Back
hess's law
Front
if 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 steps
Back
favored redox reaction
Front
+E
Back
half-life
Front
the amount of time it takes for half of a sample to disappear; t1/2=0.693/k
Back
second order rate law
Front
[a] sub. (t) = concentration of reactant A at time (t)
[a] sub. (0) = initial conc. of A
k = rate constant
t = time elapsed
Back
gas to solid
Front
deposition
Back
rate-determining step
Front
the slowest step in a reaction mechanism that determines the overall rate of the reaction
Back
rate law
Front
an expression relating the rate of a reaction to the concentration of the reactants
Back
sulfate
Front
SO4 2-
Back
half-reactions
Front
the two parts of an oxidation-reduction reaction, one representing oxidation, the other reduction
Back
elementary steps
Front
a series of simple reactions that represent the progress of the overall reaction at the molecular level
Back
cathode
Front
where reduction takes place
Back
enthalpy of solution
Front
the amount of energy released or absorbed as heat when a specific amount of solute dissolves in a solvent
Back
solid to liquid
Front
melting
Back
ineffective collisions
Front
collisions in which the conditions of the collision theory are not met (and therefore reaction does not occur)
Back
bond energy
Front
the energy required to break a bond; endothermic process (add energy)
Back
beer's law
Front
A=abc
A=absorbance
a=molar absorptivity
b=path length; the distance the light is traveling through the solution
c=concentration of the solution
Back
zero order rate laws
Front
rate does not depend on the concentration of the reactants at all therefore rate is always the same at a given temperature; rate=k
Back
heat of vaporization
Front
the energy that must be put into a liquid to turn it into a gas
Back
dichromate
Front
Cr2O7 2-
Back
first law of thermodynamics
Front
the energy of the universe is constant
Back
purpose of a salt bridge
Front
maintains electrical neutrality in the cell
Back
entropy
Front
ΔS; a measure of the randomness or disorder of the system
Back
rules of hess's law
Front
1. 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 equation
an instrument that measures the proportions of light of different wavelengths absorbed and transmitted by a pigment solution
Back
ammonium
Front
NH4+
Back
current
Front
unit: amperes (amps); the flow of electrons from one place to another
Back
enthalpy
Front
ΔH; heat of a system at constant pressure
Back
elecroplating
Front
a process that uses electric current to reduce dissolved metal cations so that they form a thin metal coating on an electrode
Back
heat of fusion
Front
the energy that must be absorbed by a solid to melt it
Back
second law of thermodynamics
Front
if a process is favored in one direction, then it cannot be favored in the reverse reaction; and an increase in entropy promotes favored reactions
Back
liquid to solid
Front
freezing
Back
ΔH°f (heat of formation)
Front
the change in energy that takes place when one mole of a compound is formed from its pure components under STP
Back
anode
Front
where oxidation takes place
Back
state functions
Front
functions 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, ΔG
Back
carbonate
Front
CO3 2-
Back
Section 5
(37 cards)
pH
Front
-log [H+]
Back
pKb
Front
-log [Kb]
Back
polyprotic acids
Front
acids that can donate more than one H+
Back
at high temperature
Front
entropy is dominant; ΔS
Back
Arrhenius acids
Front
a substance that ionizes in water and produces hydrogen ions
Back
heating/cooling curves
Front
curves that display what happens to the temperature of a substance as heat is added
Back
henderson hasselbach
Front
pH = pKa + log([A-]/[HA])
Back
weak acid
Front
most of the acid molecules remain in solution and very few dissociate
Back
Q = K
Front
the reaction is at equilibrium; voltage in a voltaic cell reaches zero
Back
amphoteric
Front
a substance that can act as both an acid and a base; ex. H2O
Back
Arrhenius bases
Front
a substance that ionizes in water and produces hydroxide ions
Back
Brønsted-Lowry acids
Front
a substance that is capable of donating a proton
Back
pOH
Front
-log [OH-]
Back
large k eq value
Front
products are favored at equilibrium
Back
pKa
Front
-log [Ka]
Back
small k eq value
Front
reactants are favored at equilibrium
Back
phase diagram (water)
Front
Back
hydration energy
Front
the energy required to break hydrogen bonds
Back
le chateliers principle
Front
states that if a stress is applied to a system at equilibrium, the system shifts in the direction that relieves that stress
Back
buffers
Front
weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH
Back
percent dissociation
Front
the ratio of the amount of a substance that is dissociated at equilibrium to the initial concentration of the substance in a solution, multiplied by 100
Back
calorimetry
Front
the measurement of heat changes during chemical reactions
Back
oxoacids
Front
acids that contain oxygen; the more oxygens, the stronger the acid
Back
a solution is at equilibrium when
Front
the rate of the forward reaction is equal to the rate of the reverse reaction
Back
specific heat
Front
the amount of heat required to the temperature of one gram of a substance by one degree celsius
Back
strong acids
Front
dissociate completely in water; reaction goes to completion and never reaches equilibrium
Back
common ion effect
Front
a decrease in the solubility of an ionic compound caused by the addition of a common ion
Back
Q < K
Front
precipitate does not form; reaction shifts right
Back
Brønsted-Lowry bases
Front
a substance that is capable of accepting a proton
Back
Kw
Front
1.0x10^-14
Back
reaction quotient
Front
Q
Back
Q > K
Front
precipitate forms; reaction shifts left
Back
nonspontaneous
Front
thermodynamically unfavored; +ΔG
Back
spontaneous
Front
thermodynamically favored; -ΔG
Back
voltage vs favorability
Front
a redox reaction is favored if voltage is (+)
Back
law of mass action
Front
the rate of a chemical reaction is proportional to the product of the concentrations of the reactants