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Test Three
Test Tree Definitions and Information up to 7.3
168
Chemistry
Undergraduate 2
03/31/2014

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Term
thermodynamics
Definition
study of energy and its transformations
Term
thermochemistry
Definition
branch of thermodynamics that deals with heat in chemical and physical changes
Term
system
Definition
part of the universe that is being focused on
Term
surroundings
Definition
everything (in reason) that is not the system
Term
internal energy E
Definition
sum of all kinetic and potential energy of each particle in a system
Term
DE =
Definition
Efinal - Einitial
Eproducts - Ereactants
q + w
Term
a change in energy of the system must be accompanied by
Definition
an equal and opposite change in energy of the surroundings
Term
releasing energy in a transfer to the surroundings
Definition
Efinal < Einitial so DE<0
Term
absorbing energy in a transfer from the surroundings
Definition
Efinal > Einitial so DE>0
Term
q symbolizes
Definition
heat
Term
heat -
Definition
energy transferred as a result of the difference in temperature between the system and the surroundings
Term
w represents
Definition
work
Term
work -
Definition
energy transferred when an object is moved by a force
Term
energy transferred into the system is
Definition
positive because the system ends up with more energy
DE is positive
Term
energy transferred out of the system is
Definition
negative because the system ends up with less energy
DE is negative
Term
the law of energy conservation
Definition
the 1st law of thermodynamics
the total energy of the universe is constant
Term
joule (J)
Definition
SI unit for energy
Term
1 J =
Definition
1 kg*m^2/s^2
Term
calorie (cal)
Definition
quantity of energy needed to raise the temperature of 1 gram of water by 1 *C
Term
1 cal = _____ J
Definition
4.184 J
Term
1 J = ___ cal
Definition
0.2390 cal
Term
the internal energy of a system is called a
Definition
state function
Term
a state function is dependent on
Definition
the current state of the system, not on the path the system takes to reach that state
Term
DE depends on
Definition
the difference between the final and initial states, not on how the change takes place
Term
pressure-volume work (PV work)
Definition
mechanical work done when the volume of the system changes in the presence of eternal pressure
Term
w =
Definition
-P DV
Term
H stands for
Definition
enthalpy
Term
enthalpy-
Definition
internal energy plus the product of the pressure and volume
Term
H =
Definition
E + PV
Term
DH =
Definition
DE + P DV
Term
the change in enthalpy equals
Definition
the heat absorbed or released at constant pressure
Term
exothermic process
Definition
releases heat and results in the decrease in the enthalpy of the system
Term
endothermic process
Definition
absorbs heat and results in an increase in the enthalpy of the system
Term
q =
Definition
c * mass * DT
Term
heat capacity -
Definition
quantity of heat required to change its temperature by 1 K
Term
heat capacity =
Definition
q / DT
Term
specific heat capacity -
Definition
quantity of heat required to change its temperature of 1 gram of the object by 1 K
Term
c represents
Definition
specific heat capacity
Term
c =
Definition
q / (mass * DT)
Term
molar heat capacity -
Definition
quantity of heat required to change its temperature of 1 mole of the substance by 1 K
Term
C represents
Definition
molar heat capacity
Term
coffee cup calorimeter
Definition
device that measures the heat transferred at constant pressure
Term
bomb calorimeter
Definition
device measures the heat released at constant volume
Term
thermochemical equation
Definition
balanced equation that includes the enthalpy change of the reaction
Term
Hess' Law
Definition
the enthalpy change of an overall process is the sum of the enthalpy changes of its individual steps
Term
DHoverall =
Definition
DH1 + DH2 + DH3...
Term
standard state for a gas
Definition
at 1 atm and ideal behavior
Term
standard state for a for a substance in aqueous solution
Definition
1 M concentration
Term
standard state for a for a pure substance (element or compound)
Definition
the most stable form of the substance at 1 atm and 25*C (298K)
Term
in a formation equation
Definition
1 mol of a compound forms from its elements
Term
standard enthalpy of formation
Definition
enthalpy change for the formation equation when all the substances are in their standard states
Term
the standard enthalpy of reaction is
Definition
the sum of the standard enthalpy of formation of the products minus the sum of the standard enthalpy of formation of the reactants
Term
examples of fossil fuels
Definition
petroleum, coal and natural gas
Term
Kinetic Energy
Definition
The energy associated with motion
Term
Thermal Energy
Definition
Motion of atoms, molecules or ions at the submicroscopic level
Term
Mechanical Energy
Definition
Motion of a macroscopic objects like a moving basketball or airplane
Term
Electrical Energy
Definition
Movement of electrons through a conductor
Term
Acoustic Energy
Definition
The compression and expansion of molecules in the transmission of sound.
Term
Potential Energy
Definition
The energy associated with an objects position
Term
types of kinetic energy
Definition
Acoustic Energy
Electrical Energy
Mechanical Energy
Thermal Energy
Term
Gravitational Energy
Definition
Energy possessed by a ball held above the floor or by water at the top of a water fall
Term
Chemical Energy
Definition
Energy stored in fuels or in chemical bonds
Term
Electrostatic Energy
Definition
The energy associated with the separation of two electrical charges.
Term
Types of Potential energy
Definition
Gravitational Energy
Chemical Energy
Electrostatic Energy
Term
Law of Conservation of Energy
Definition
Energy can neither be created nor destroyed
Term
w stands for
Definition
Energy transferred as work to or from the system
Term
Internal Energy
Definition
The formal name for the quantity E.
Internal energy in a chemical system is the sum of PE and KE of the atoms, molecules or ions
Term
enthalpy is
Definition
equal to the amount of energy transferred as heat at a constant pressure.
Term
If H is negative,
Definition
energy is transferred as heat from the system to the surroundings. Exothermic.
Term
If H is positive,
Definition
energy is transferred as heat from the surroundings to the system. Endothermic.
Term
The temperature of an object is a measure of
Definition
its ability to transfer energy as heat.
Term
The higher the temperature,
Definition
the greater the thermal energy of the materials atoms, ions or molecules
Term
Thermal Equilibrium
Definition
When two objects which were once at different temperatures, reach the same temperature
Term
Energy transfer as heat will occur spontanesosly from _____ to ______
Definition
the higher temperature material to the lower temperature material
Term
Calorimetry
Definition
The method by which the energy evolved or required as heat in a chemical of physical process is measured.
Term
Change of State
Definition
conversion of a substance from one physical state to another, i.e. from a liquid to a solid or from a liquid to a gas
Term
Heat of Fusion
Definition
The energy transferred as heat that is required to convert a substance from a solid to a liquid
Term
Heat of Vaporization
Definition
The energy transferred as heat that is required to convert a substance from a liquid to a gas
Term
The superscript o indicates that
Definition
the reaction has been run at standard conditions.
Term
Enthalpy changes are specific to
Definition
the reaction being carried out. State of the product produced, is important as are the amounts of products and reactants.
Term
The enthalpy change depends on the
Definition
number of moles of reaction. That is how many times the as written reaction is carried out.
Term
Electromagnetic Radiation
Definition
Characterized by wavelength and frequency and includes light, microwaves, television and radio signals x-rays, and other forms of radiation
Term
wavelength
Definition
ambda, , the distance between successive crest or high points of a wave. The distance is usually measured in m or nm
Term
frequency
Definition
nu, , refers to the number of waves that pass a given point in some unit of time, usually per second. The unit of frequency, written as s-1 or 1/s is called hertz.
Term
Clight =
Definition
Clight = 2.99792458 x 108m/s
Term
Magnetic vector moves _______ to that of the electric vector
Definition
perpendicular
Term
Nodes:
Definition
where the wave changes from positive to negative
Term
Plank Assumed
Definition
that the EMR emitted was caused by vibrating atoms called oscilators. And if each oscilator had a frequency, and the emitted radiation had a certain energy, the following eqn could be written.
Term
Plank’s Constant:
Definition
h = 6.6260693 x 10 -34 J*s
Term
E=
Definition
h * wavelength
Term
Photoelectric Effect
Definition
electrons are ejected when light strikes the surface of a metal.
Term
The energy of each photon is proportional to
Definition
the frequency of the radiation as defined by Planck’s eqn.
Term
Einstein
Definition
Photoelectric Effect
Term
Line Emission Spectrum
Definition
The spectrum obtained from passing a beam of light from the excited sample through a prism.
Term
Balmer Equation
Definition
1/ lambda = R (1/22 - 1/n22), where n is an integer and > 2
Term
Rydberg Constant
Definition
R = 1.0974 x 107 m-1
Term
Balmer series.
Definition
The 4 visible lines in the spectrum of hydrogen
Term
Bohr derived an equation for
Definition
the energy possessed by the single electron in the nth orbit of the H atom
Term
Bohr Equation
Definition
En = - Rhc / n2
Term
n defines the
Definition
energies of the allowed orbits in the H atom
Term
deBroglie
Definition
Proposed that matter which was normally considered a particle, could also exhibit wave properties. Previously for light in the photoelectric effect.
Term
Bohr Model:
Definition
That both the energy and the location for the electron in the hydrogen atom can be described accurately
Term
Heisenberg:
Definition
Determined that for an object such as an electron in an atom, it is impossible to determine accurately both its position and its energy.
Term
Heisenberg Uncertainty Principle:
Definition
any attempt to determine accurately either the location or the energy will leave the other uncertain.
Term
Schrodinger
Definition
Developed quantum mechanics or wave mechanics. Uses mathematical eqns of wave motion to generate wave functions which are used to describe a electrons in the atom.
Term
the principle quantum number
Definition
n
Term
The value of n, is
Definition
the primary factor in determining the energy and size of an orbital.
Term
For any given atom, the greater the value of n,
Definition
the greater the size of the orbital.
Term
Orbitals are grouped into _____ .
Definition
subshells
Term
each subshell is characterized by a different value of ____
Definition
I
Term
I defines the characteristic
Definition
shapes of the orbitals.
Term
mf is related to the
Definition
orientation in space of the orbital within a subshell.
Term
Paramagnetic
Definition
Elements or compounds that have unpaired spins and are attracted to magnets.
Term
Diamagnetic
Definition
Substances in which all the electrons are paired (with 2 electrons in each pair, having opposite spins) experience a slight repulsion when subjected to a magnet
Term
electron spin quantum number
Definition
ms
Term
frequency
Definition
the number of cycles a wave undergoes per second
Term
electromagnetic radiation consists of
Definition
energy propagated by electric and magnetic fields that increase and decrease in intensity as they move through space
Term
visible light, x rays and microwaves are examples of
Definition
electromagnetic radiation
Term
wavelength
Definition
the distance between any point on a wave and the corresponding point on the next crest of the wave
the distance the wave travels in one cycle
Term
speed of light (c) =
Definition
wavelength * frequency
Term
amplitude
Definition
the height of the crest of wave or the depth of the trough
Term
the amplitude of a wave is related to the
Definition
intensity of the radiation
Term
types of waves by increasing wavelegth
Definition
gamma
x-ray
ultraviolet
visible
infrared
microwave
radio
Term
types of waves by increasing frequency
Definition
radio
microwave
infrared
visible
ultraviolet
x-ray
gamma
Term
visible light goes from
Definition
400 nm (violet) to 750nm (red)
Term
refraction
Definition
when a light wave passes through on medium and into another and the speed of the wave changes, making the wave bend in shape
Term
dispersion
Definition
white light separates into its component colors when it passes through a prism
Term
diffraction
Definition
when a wave strikes against an object and it bends around it
Term
blackbody radiation
Definition
when a solid object is heated to about 1000 K and it begins to emit visible light
Term
the quantum theory was created by
Definition
Planck
Term
the photon theory was created by
Definition
Einstein
Term
wavelength and frequency have a _____ relationship
Definition
reciprocal
Term
line spectrum
Definition
a series of fine lines at specific frequencies separated by black spaces
Term
Rydberg equation predicts
Definition
the position and wavelength of any line in a given series
Term
Rydberg equation
Definition
(1 / wavelength) = R ((1 / n1^2) - (1 / n2^2))
Term
the Hydrogen model atom was created by
Definition
Bohr
Term
Postulates of Bohr's Hydrogen Atom Model
Definition
the H atom has only certain energy levels
the atom does not radiate energy while in one of its stationary states
the atoms changes to another stationary state only when absorbing or emitting a photon
Term
ground state
Definition
when the electron is in the first orbit, is closest to the nucleus and the H atom is in the lowest (first) energy level
Term
excited state
Definition
if the electron is in any orbit other than the first orbit
Term
an atomic spectrum (is/ is not) continuous because
Definition
is not; the atom's energy is not continuous, but rather has only certain states
Term
an atom changes energy by
Definition
absorbing or emitting a photon of specific energy
Term
Bohr's Equation
Definition
DE = Efinal - Einitial = -2.18x10^-18 J ((1/ nfinal^2) - (1/ninitial^2))
Term
emission spectrum is produced when
Definition
atoms in an excited state emit photons characteristics of an element as they return to lower energy states
Term
absorption spectrum is produced when
Definition
atoms absorb photons of certain wavelengths and become excited from lower to higher energy states
Term
a spectrometer is used to measure
Definition
the concentration of a substance in a solution
Term
absorbance -
Definition
the amount of light of a given wavelength absorbed by a substance
Term
absorbance is proportional to
Definition
the amount of molecules
Term
Bohr proposed that
Definition
electrons move in a fixed orbit
Term
atomic orbit
Definition
mathematical description of the electron's matter-wave in three dimensions
Term
n represents
Definition
the principle quantum number
Term
the principle quantum number indicates
Definition
the relative size of the orbital and therefore the relative distance from the nucleus
Term
l represents
Definition
angular momentum quantum number
Term
angular momentum quantum number indicates
Definition
the relative shape of the orbital
Term
ml indicates
Definition
the magnetic quantum number
Term
the magnetic quantum number describes the
Definition
3D orientation of the orbital
Term
the atoms levels are given by the
Definition
n value
Term
the atoms levels are divided into sublevels that are given by the
Definition
l value
Term
l = 0 is what sublevel
Definition
s
Term
l = 1 is what sublevel
Definition
p
Term
l = 2 is what sublevel
Definition
d
Term
l = 3 is what sublevel
Definition
f
Term
No more than ____ electrons can be in an atomic orbital.
Definition
2
Term
Pauli Exclusion Principle
Definition
No two electrons can have the same set of quantum numbers.
Term
Aufbau Principle
Definition
The procedure in which electrons are assigned to orbitals.
Term
Atomic Size is related to
Definition
the distance between atoms in a sample of the element
Term
For the main group elements, atomic size generally
Definition
Increases going down a group due to the larger number of outer (valence electrons)
Decreases going across a period due to the larger effective nuclear charge
Term
Ionization Energy
Definition
The energy required to remove an electron from an atom in the gas phase.
Term
Ionization energies general
Definition
general increase across a period due to the increase in effective nuclear charge
decrease down a group due to the increase in size
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