Pchem test 3.txt
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Pchem test 3.txt
fileName "Pchem test 3"
Frequency and wavelength relation
Lambda v = c
Reciprocal of frequency (time between peaks)
Why use sin with spring constant?
Twice differentiated is equal to sin
Where is natural frequency iused
Simple harmonic motion
Intersection of wave with 0
Time between peaks, inverse frequency
When is sin =0
For any integer*pi and for 0
Where is energy maximized?
What is h
Plancks constant. Ties wavelength to energy per packet.
Hv= kinetic energy of electron+work to remove electron
Minimum frequency (w/h) to remove electron from surface
Energy level at which electron emit no energy
How is hv tied to changes in energy state?
Energy needed to move an electron to infinity
Value used in deriving wavelength average from mjultiple spectral lines?
Crystals are distinguished from amorphous solids by
Representative unit of molecular structure repeated at fixed intervals.
Structural init of a crystal
Unifor arangement of points in space repeatyed in cristal styructure.
2 d lattice
Minimum volume of the 3d crystal
Held together by temporary van der waal forces
Held together by interaction of shared ions
Atoms with similair charges share electrons to comlete orbital
Partial charges bresponsible for bonds of this type.
Intermediate type bonding.
A large anions field of electrons is disturbed by a nearby ion
Sea of electron
Lattice energy (inc E_c)
The energy of a crystal lattice
Speed of light
H/i d/dx= -ihd/dx
How do we determine if gtwo functions orthoganol?
Integral of a*b dtau =0
Energy of sublimation
Energu to go from solid to gas
Order of lattice strength
Van der waal- hydrogen-metalic-covalent -ionic
London vanderwaal bond energy
Sum of forces modelled by leonard jones method. Based on partial charges as function of (1?r)^12 -(1/r) ^6
Bond energy of metal
Enthalpy of sublimation to mono atomic gas. Found as function of vapor pressure
Inside the molecule
Melting point increases with
Bond energy of hbond or dipole dipole
Based on partial charges as function of (1/r) ^6
Bond energy of cobvalent solids
Enthalpy to convert into gas phase, can be calculated with density functional theory
Ionic solid crystal lattice energy
Calculated using hesss law
Hesss law steps (5)
1) calculate metals heat of sublimation
2) calculate metal gas ionization energy per chatge
3) if gas is diatomic, calculate dissociation energy
4) calculatge gass electron affi nity for charge number
5) sum and subtract solids enthalpy of formation
Ionic crystal internal bond energy
Adsorption onto a surface caused by van der waals forces. Typically week and unimporgtant. Can however occur quickly and spontaneously
Covalent adsorption onto a surface modelled by langmuir. Slow and rarely spontaneous due to high activation energy
When does surface become saturated in langmuir model?
High vapor pressure leads to 100% unilayer coverage
What is sign of enthalphy h of adsorption
What is sign of entropy s of adsorption
What is sign of gibbs for adsorption
Difference between graph of langmuir vs bet coverage.
Langmuir reaches a flat surface at 100% coverage by monolayer.
BET can have multiple layers so aftwr initial asymptote starts rising again
Bimolecular reaction catalyzed by surfacwe. At some level (stoich ratio) rate peaks and then tapers off if conc of one increases while other stay constant
Langmuir hinschelwood if one or both sunstance sorb weak
Then that substance will drop out of bottom of eqjatipon
Competitive adsorption, but b need bond surface and a must be gas for reaction
Linier momentum operator
Kinetic energy operator
-i-hat^2/2m del^2 + E_HAT_P
Blackbody average energy
E_bar = k_b T
State n in which electron emitsz no radiatoin
Change in energy between state 1 and 2
Planck*frequency = E2-E1
Energy needed to remove elecytron
Shows average frequency (1/wavelength) of an emission spectra
Energy to momentum relations
Momentum * speed of light
Wavelength to plank relations (2)
Heisenburg 3 forms
Inc location* inc momentum >= H_BAR/2
incE Inc t >=h_bar/2