AP Chemistry terms

Terms Definitions
double bond
Cr2O7 [[-2]]
alpha rays
C2O4. Charge: 2-
Flame Test K+
Number of Protons
Atomic Number
more product than reactants
Number of known elements?
according to the Bronsted-Lowry definition, a compound that donates a proton, or H3O+ ion
the mixing of gases. (5.7)
What is heat capacity?
chemical equilibrium
balance between opposing processes determining the relative numbers of ions and neutral molecules
J.J. Thomson
discovered electrons, introduced "plum pudding" model
two or more atoms bonded together
atomic masses
the weighted averages of isotopes
(chemistry) a substance formed by chemical union of two or more elements or ingredients in definite proportion by weight
Bond Angle of Bent (1:2)
Less than 120º
K = C + 273.15
Celsius to Kelvin
homogeneous mixture of two or more substances in a single physical state
combustion reaction
vigorous and exothermic reaction that takes place between certain substances, particularly organic compounds, and oxygen
In rxn mechanisms, these are species that appear in steps but cancel out of the balanced equation
an organic compound that contains a carbonyl group to which at least one hydrogen atom is attached.
another word for groups, columns of elements on the periodic table
Elements that are usually solids at room temperature, exhibit high electrical and heat conductivity, and appear lustrous.
Ernest Rutherford
Revealed three types of radiation: alpha, beta and gamma.
The conversion of a gas into a liquid
combining a sample of solution with a standard solution (reagent solution of known concentration)
vapor pressure reduction
colligative property in which the pressure of the vapor over a solvent is reduced when a nonvolatile solute is dissolved in the solvent; vapor pressure reduction is directly related to the concentration of a solution
Neils Bohr
took quantum theory and predicted that electrons orbit the nucleus at specific radii (worked for simple elements)
Chemical bond
the force or, more accurately, the energy, that holds two atoms together in a compound
Spin Pair
Refers to electrons filling an orbital shell.
redox reaction
any reaction involving a transfer of electrons and a change in oxidation state
periodic table
a chart showing all the elements arraigned in columns with similar chemical properties.
A polyatomic ion that contains one or more oxygen atoms.
molar heat capacity
heat capacity of q mol of substance
clay triangle
is used as a support for porcelain crucibles when being heated over Bunsen burner.
internal energy
property of system that can be changed by a flow of work, heat, or both; ΔE= q+w, where ΔE is the change in the internal energy of the system, q is heat, and w is work
K for a reverse reaction
1/ K of forward reaction
Methyl orange is an indicator with a Ka of 1x10^-4. Its acid form, HIn, is red, while its base borm, In-, is yellow. At pH 6.0, the indicator will be
C) Yellow
sigma molecular orbital
a molecular orbital in which the electron probability of both molecular orbitals is centered along the line passing through the two nuclei
the point in a titration at which the indicator changes color
heat of vaporization
amount of heat necessary to vaporize a given amount of liquid
Colored Solution Br and I
dark brown color in np solvent
You have two salts, AgX and AgY, with very similar Ksp values. You know that Ka for HX is much greater than Ka for HY. Which salt is more soluble in acidic solution?
B) AgY
intensive property
a property that does not depend on how much matter is being considered
Keq and multistep process
If rxns are added to obtain overall rxn, the K is just the product of the K's of the elementary steps
Find cell potential under nonstandard conditions when not under equilibrium
Ecell= E°cell - (RT/nF)lnQ

R = 8.31
Most salts containing alkali and ammonium ions are soluble
Solubility 2 (Li+, Na+, K+, Cs+, Rb+)
Predicting Nuclear Stability: Mass # < atomic weight
nucleus will try to lose protons and gain neutrons; expect positron emission or electron capture
10^-2 (c)
ClO2 [[-1]]
Bonding Pair: 1:2
Compounds containing NO3-
Flame Test Ca2+
Color of Beryllium
Steel Gray
speed of light
3E8 m/s
the group 2a elements
oxidation occurs at the _____
the smallest representative particle of an element.
Trigonal Planar (degree/ hybridization)
120/ sp2
expresses the concentration of a solution as the number of moles of solute in a liter of solution (M = moles solute / volume of solution in liters)
Dmitri Mendeleev
creator of original periodic table
ionic bonding
the electrostatic attraction between oppositely charged ions.
Kilogram (kg)
SI base unit of mass
Bond Angle of Seesaw
90º, 120º, and 180º
Hund's rule
for degenerate orbitals, the lowest energy is attained when the number of electrons with the same spin is maximized, electrons will occupy orbitals singly to the maximum extent possible
process in which water molecules pull solute particles into solution and form a sphere around them
an organic compound produced by the reaction between a carboxylic acid and an alcohol
Strong Acids
HCl, HBr, HI, HNO3, H2SO4, HClO4
alpha particles
particles that are identical to helium-4 nuclei consisting of two protons and two neutrons, 4/2He
the small, dense center of positive charge in an atom.
Oxidation Rule #3: ______ has an oxidation level of -1 in all compounds
Resulting material, right side of the equation
Electron Affinity
The energy change that accompanies the addition of an electron to an atom. Fluorine has the highest affinity - the closer it is to Fluorine, the higher it is.
aqueous solutions
solutions in which water is the dissolving medium
process in which ions leave a solution and regenerate an ionic solid
John Dalton
proposed basic idea of elements, which combine to form compounds which always have same ratio of each element
a substance that contains a mixture of elements and has metallic properties
E°cell information
get V from appendix
if the half reaction is backwards, change the sign of the Voltage
Percent Composition
Add together atomic masses of a compound to equal the molar mass. Divine the atomic mass by the molar mass then multiply by 100%. This equals percent composition.
polyatomic ion
an ion containing a number of atoms.
Pure Substance
Matter that has a fixed composition and distinct properties.
The numbers appearing in front of the chemcial formula
electrical conductivity
the ability to conduct an electrical current
Magnetic Stir Bars
covered in Teflon that are dropped into liquid samples. When placed on a stir plate the magnetic bar spins and stirs the liquid sample.
first law of thermodynamics
energy of the universe is constant
Reaction order
- With respect to x = [x]^whatever
- of an entire reaction is the sum of all the exponents
1 mole of H3PO4 reacts with 2 moles KOH produces water and...
conjugate acid
the species formed when a proton is added to a base
spectator ions
ions present in solution that do not participate directly in a reaction
acidic hydrogen
hydrogen atom that an acid may lose as an H3O+ ion
Heat of Formation
change in energy that takes place when one mole of a cpd is formed from its component pure elements under std state conditions; delta H sub f is always zero for a pure element
You have a solution consisting of .10 M Cl- and .10 M CrO4^2-. You add .10 M silver nitrate dropwise to this solution. Given that the Ksp for Ag2CrO4 is 9.0x10^-12, and that for AgCL is 1.6x10^-10, which of the following will precipitate first?
A) Silver chloride
what does quantized mean?
- electrons only exist at certain energy levels
- &quot; a stairs&quot;
Van der Waals Equation
at low temp and/or high press, gases behave less than ideally; adjusts ideal gas equation to take nonideal conditions into account; volume of gas becomes significant; gas molecules attract one another and stick together (dipole-dipole and London dispersion forces)
moles in comparison to gases
mole = PV/RT (R = 0.0821 L-atm/mol-K)
Percent Deviation (measure precision)
Dev = 100 X Sum|trial - mean| / N(mean)
First Order Rate Law units and graph
1/s or 1s^-1, graphed with ln[A] on y-axis, slope -k
10^6 (M)
CO3 [[-2]]
Compounds containing ClO3-
Flame Test Sr2+
Bonding Pair: 0:3
Trigonal Planar
Nuclear force
non-electrical, non-gravitational force that holds nucleus together; unstable nuclei attempt to increase stability by altering # of protons and neutrons (radioactive decay)
single positive electric charge
color of solution with fe3+
have oxidation states of zero
moles under STP (volume
liters/(22.4 L/mol)
energy transferred from a hotter object to a colder one
Dipole-dipole forces
forces between neutral, polar molecules (+ end of one attracts to - end of another)
mixures vary in apperance throughout sample
a substance that produces hydrogen ions in solution; a proton donor.
meter (m)
SI base unit of length
The formation constant, a special term used to describe the formation of complex ions
electron density
another way of expressing probability: regions probability of finding the electron are said to be regions of high electron density
osmotic pressure
pressure required to prevent osmosis; arises when the flow of solvent particles from a dilute solution to a concentrated solution across a semipremeable membrane results in unever heights of the solutions of either side of the membrane
complex ion
charged species consisting of metal ion surrounded by ligands
Haber process
used in industrial preparation of ammonia from hydrogen and nitrogen gases
acid rain
rainwater that has become excessively acidic because of absorption of pollutant oxides, notably SO_3, produced by human activities.
an element that gives up electrons relatively easily and is lustrous, malleable, and a good conductor of heat and electricity.
C₂H₅OH and CH₃OCH₃ are examples of...
condensed structural formula
Atoms that have gained one or more electrons and carry a negative charge. (-)
base dissociation constant
constant that indicates the strength of a base; derived from the equilibrium constant for the base's dissociation in water
Ionization energy
energy required to remove an electron from an atom. Because of increased nuclear attraction, increases from L to R, increased shielding means decreases from T to B on periodic table. Second greater than first.
glass electrode
electrode for measuring pH from the potential difference that develops when it is dipped into an aqueous solution containing H+ ions
Dipole Movement
-the product of the distance between charges and the strength of the charge; a measure of the polarity of a molecule
is the component of the solution that is dissolved in the solvent.
forms of energy
heat, light, sound, mechanical energy, electrical energy, chemical energy
Physical Change
Changes, such as phase change, that occur with no change in chemical composition.
Physical Changes
Change in physical appearance but not a change in composition. (e.g. tearing a piece of paper, smashing chalk, etc.)
strong base
a metal hydroxide salt that completely dissociates into its ions in water
energy used to cause an object to move against a force, w = F x d (force x distance)
gas measuring tube
A very precise measuring tube that measures the volume of gas released from a reaction.
Carbon steel
an alloy of iron containing up to about 1.5% carbon
Excited state
One or more inner orbital is not filled
reaction quotient, Q
a quotient obtained by applying the law of mass action to inital concentrations rather than to equilibrium concentrations
basic oxides
a ionic oxide that dissolves in water to give an basic solution
polar molecule
a molecule that has a permanent dipole moment
hydronium ion
ion formed by the addition of a proton to a water molecule; accounts for the properties of acids
Common Ion Effect
solubility of salt can be decreased by adding cpd with common ion, thereby causing reverse rxn to occur; in general, when two salt solutions that share a common ion mix, salt with lower Ksp will precipitate first
A certain indicator HIn has a pKa of 9.00 and a color change becomes visible when 7.00% of it is In-. At what pH is this color change visible?
D) 7.88
Heisenbergy uncertainty principle
- impossible to know both position and momentum of e-
- electron orbital is probabilty of e- found in that region
Hess's Law
if rxn can be described as a series of steps, delta H for overall rxn is simply the sum of the delta H values for all the steps
Relationships to the Periodic Table
EN (attract electron)to the right and up
Atomic Radius to the left and down
IN (remove electron)to the right and up
valence shell electron-pair repulsion (VSEPR) model
a model whose main postulate is that the structure around a given atom in a molecule is determined principally by minimizing electron-pair repulsions.
Liquid to solid (in terms of energy release)
Energy is released by the substance intermolecular forces are being strengthened
perchloric acid
HCO3 -1
Gay-Lussac's law
Bonding Pair: 1:4
Dilution formula
M1V1= M2V2
spontaneous emission of radiation
mol solute/ kg solvent
Ideal Gas Law
PV = nRT
the capacity to do work
Hydrogen Sulfate or Bisulfate
HSO4. Charge: -
property of substances with no unpaired electrons are weakly repelled from a magnetic field, much weaker effect than paramagnetism
two parts of an oxidation-reduction reaction, one representing oxidation, the other reduction
An organic compound obtained by substituting a hydroxyl group (-OH) for a hydrogen on a hydrocarbon.
the cetnral core of an atom
unsaturated hydrocarbon
compound with a carbon-carbon multiple bond
the existing of liquids or solids (under ordinary conditions) in the gaseous state
Hydrogen bonds
similar to dipole-dipole, + charged hydrogen end of molecule attracted to - charged end of another molecule (usually with very EN element F, O, or N)
study of the interchange of chemical and electrical energy
elements that have all of their electrons spin paired; elements with all of their sublevels completed; not strongly affected by magnetic fields
EX: helium, beryllium, and neon
dumbbell shaped
orbitals of p subshells are what
J. J. Thomson
measured charge-to-mass ratio of electrons with cathode rays
Lewis structure
show each electron pair shared between atoms as a line, and the unshared electron pairs as dots
bonds in which electrons are shared unequally
polar bond
Actinide series
a group of 14 elements following actinium in the periodic table, in which the 5f orbitals are being filled
Phase changes to know
Melting, Freezing aka Fusion, Vaporization, Condensation, Sublimation, Deposition
concentration cell
a galvanic cell in which both compartments contain the same components, but at different concentrations. (17.4)
when any electrons are unpaired in an element
aufbau principle;e
states that when building up the electron configuration of an atom, electrons are placed in orbitals, subshells, and shells in order of increasing energy
molecular orbitals
can hold two electrons with opposite spins, and the square of the molecular orbital wave function indicates electron probability
the lements in a vertical column of the period table
soluble with F-, PO4^3-, CO3^2-, S2-
NH4+ Na K Li
trigonal bipyramidal, seesaw
5 electron domains: 4 bonding, 1 nonbonding; s,p,p,p,d atomic orbital set, five sp3d hybrid orbital set (SF4)
Bond energy
the energy required to break a given chemical bond
Bohr's three postulates
1. only orbits of certain radii, corresponding to certain definite energies, are permitted for the electron in a hydrogen atoms
2. an electron in a permitted orbit has a specific energy and is in an "allowed" energy state. An electron in an allwed energy state will not radiate energy and therefore will not spiral into the nucleus.
3. energy is emitted or absorbed by the electron only changes from from one allowed energy state to another. This energy is emitted or absorbed as a photon.
(atm) a unit of pressure equal to 760 torr, 1 atm= 101.325 kPa.
hunds rule
states that when an electron is added to a subshell, it will always occupy an empty orbital if one is available
bonding pair
an electron pair found in the space between two atoms.
Anion Nomenclature 3
anion derived by adding H+ to an oxyanion are named by adding as a prefix the word hydrogen or dihydrogen, as appropriate (CO3 2- carbonate ion, HCO3 - hydrogen carbonate ion, PO4 3- phosphate ion, H2PO4 - dihydrogen phosphate ion)
atom or group of atoms that has a net positive or negative charge
principle quantum number
(n) the quantum number relating to the size and energy of an orbital; it can have any positive integer value. (7.6)
Neutron: (3 things)
- 1/0 n
- Slightly heavier than a proton
- Changes into a proton when a beta particle is emitted
pascal (Pa)
SI unit of pressure N/m^2, 1 Pa = 1 N?m^2
binary ionic compounds type I
cation and anion, take the -ide ending
pressure-volume work (P-V work)
w = -P deltaV, where deltaV is change in volume (Pressure is constant), when change in volume is positive, work done by the system is negative
Heat capacity (C sub p)
measure of how much temp of an object is raised when it absorbs heat; ratio of delta H to delta T (temp)
Standard Temp and Pressure for Gases
1 atm = 760 mmHg, 0 degrees Celsius = 273 K
group 6A
Compounds Containing CO32-
R in PV=nRT
Pauli Exclusion Principle
1 atm to torr
2+ cation and 1+cation
study of the quantitative relationships
in chemical formulas and equations.
-(+) side
-Higher E
- e- enter
1 dm = ____ m
Mendeleev and Meyer
developed periodic table
Mendeleev predicted several elements and some of their properties
equilibrium constant
constant that relates the concentration of reactants and products of a reversible reaction (each raised to the power indicated by its coefficient in the balanced chemical equation) at equilbrium; indicates the extent to which a reversible reaction proceeds
measure of how closely individual measurements agree with one another
Write the name(s) for: HI
hydoiodic acid
Vitamin D, many hormones (including steroid hormones) & bile salt
beta rays
rays' particles have 1- charge, smaller than alpha particles, high speed electrons, considered radioactive equivalent of cathode rays
Group 7A elements with silver, mercury (I), and lead
Ionic compound
solid held together by the electrostatic attractions between ions that are next to one another in a lattice structure
Bohr's model
"microscopic solar system" - electrons orbited the nucleus. He assumed that electrons move in circular orbits around the nucleus. However, according to classical physics, an electron should eventually lose enough energy and spiral into the nucleus. This obviously doesn't happen because many elements are stable. Bohr assumed the prevailing laws of physics were inadequate to describe all aspects of atoms.
visible light spectrum
violet has the shortest wavelength, red has the longest
400-750 nm
Unexpected cases
look for repulsion from paired electrons, unusual shielding behavior
de Broglie hypothesis
all matter has wave charac
whatever occupies space and can be perceived by our senses
Aufbau Principle
- when building an electron configuration of atom, electrons are placed in orbitals, subshells, and shells in order of increasing energy
atomic weight
average atomic mass of each element (expressed in amu)
bond angles
decrease as the number of nonbonding electron pairs increase
the study of materials and the changes that materials undergo
isoelectronic ions
ions containing the same number of electrons
Colligative property
depends on number of solute particles in solution; identity is not important
Weak electrolyte
a material which, when dissolved in water, gives a solution that conducts only a small electric current
Periodic Trends
properties that can be predicted by nothing an element's position on the periodic table
Celsius Scale
A temperature scale on which water freezes at 0 degrees and boils at 100 degrees at sea level.
carboxyl group
the ----COOH group in an organic acid
Dmiritri Medeleev and Lothar Meyer
- developed periodic table
Mass Number
- total number of protons and neutrons in an atom
- electrons (e-) only represent 1/1837 of a mass unit
∴ not included in a mass number
Group IA Hydroxides
Only __________ are very soluble and should be written as separate ions
Arrhenius Acid/Base
Acid - ionizes in water and produces H+ ions; Base - ionizes in water and produces OH- ions
Henry's law
the amount of gas dissolved in a solution is directly proportional to the pressure of the gas above the solution
The ratio of an object's mass to its volume.
How can you calculate the molality?
kg of solvent/ moles
oxidation number
the actual charge of an atom in a substance (if it is monoatomic), or hypothetical charge assigned ot the atom using a set of rules
Bonding molecular orbital
an orbital lower in energy than the atomic orbitals or which it is composed
Stoichiometric (equivalence) point
the point in a titration when enough titrant has been added to react exactly with the substance in solution being titrated
hybrid orbitals
a set of atomic orbitals adopted by an atom in a molecule different from those of the atom in the free state
Energy of an electron
E(n) = (-2.178 x 10^-18) / n^2 joules
Law of Conservation of Matter
in a chemical change, matter can neither be created nor destroyed. it can only change from one form to another
Quantum number m sub s
Spin - ea. orbital contains two elec., one with a negative spin, one with a pos. m = 1/2, -1/2
Find the oxidation numbers of PbCO₃
Pb = +2
C = +4
O = -2
How to find the energy of the electron of Hydrogen atom?
E = (-2.178x10^-18)/ n^2 Joules

n is the shell (principal quantum number)
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