Exam 2 equation cheat sheet
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∆E = q + w
∆H = qp = ∆E + P∆V
∆E = qv
w = -P∆V
∆Euniverse = ∆Esystem + ∆Esurrounding
For isolated systems, qsurrounding + qsystem = 0
q = HeatCapacity∆T
q = cm∆T
q = Cmol∆T
w = -P∆V
∆Hrxn˚= ∑n∆Hf˚products–∑n∆Hf˚reactants
cwater (liq) = 4.184 Jg-1K-1 , cwater (ice) = 2.03 Jg-1K-1
c=vλ
c = 3.00 x 108 ms-1
∆E = hv = Ephoton
h = 6.626 x 10-34 kgm2s-1
∆E = h c
λ
λ= h
mu
∆x m ∆u ≥ h
4π
Hϕ = Eϕ
1
1
1
–
=R
λ
n1 2 n 22 , R = 1.097 x 107 m-1
∆E = E final – E initial = -2.18 x 10 -18J
•
1
n final2
–
1
ninitial2
Study guide: Exam 2 covers Chapter 6 & 7 only
You’ll be given cheat sheet above + periodic table.
If you print the above cheat sheet on a 8.5” x 11” piece of paper, you are
allowed to write notes on the printed side of the sheet ONLY (ie. The side with
the equations on it, but NOT the back side). You can write whatever you want,
however much you want, as long as it fits on that page. If you do, attach the
sheet onto your exam when you turn it in.
You should know/ be able to:
• Basic definition of thermochemistry terms:
o Thermodynamics, thermochemistry, system, surrounding, internal energy,
heat, work, joule, calorie, law of conservation of energy/ first law of
thermodynamics, state function, path function, enthalpy, pressure-volume
work, exothermic, endothermic, energy diagram, heat capacity, specific
heat capacity, molar heat capacity, calorimeter, constant pressure
calorimetry, constant volume calorimetry, coffee-cup calorimeter, bomb
calorimeter thermochemical equation, Hess’s law, standard enthalpy of
reaction, heat of formation equation, standard enthalpy of formation,
standard state
• Complete calculations for calorimetry problems
o Constant pressure calorimetry
§ Hot object mix with cold object
§ Find ∆Hrxn of a aqueous reaction
o Constant volume calorimetry
§ Find ∆Erxn or heat of combustion
• Read or draw energy diagrams
• Complete stoichiometry problems for thermochemical equations
• Use Hess’s law to find ∆Hrxn
• Write heat of formation reaction equations
• Find ∆Hrxn˚ if given ∆Hf˚ values
• Basic definitions of quantum/atomic theory terms:
o Electromagnetic radiation, frequency, wavelength, speed of light,
amplitude, electromagnetic spectrum, ultraviolet, infrared, refraction,
diffraction, interference, quantum number, Planck’s constant, quantum,
photon, line spectrum, quantum mechanics, wave function, atomic orbital,
Schrodinger equation, electron density diagram, electron cloud
depictions, radial probability distribution plot, principle quantum number,
angular momentum quantum number, magnetic quantum number, orbital,
energy level, sublevel/subshell, node,
• Calculate the wavelength of any wave given frequency, or frequency given
wavelength
• Identify the classification of electromagnetic waves given wavelength or
frequency (Figure 7.3 will be provided, P.288)
• Explain the different behaviors between matter and waves
• Explain how black body radiation and photoelectric effect led to the discovery
that energy is quantized (also know what the mystery was before we realized
energy is quantized)
• Explain the Bohr model of an atom, how it explains line spectra and what its
limitations are
• Use the Rydberg equation or Bohr’s equation to calculate the energy or
wavelength of a photon needed to excite/de-excite an electron to certain energy
levels
• Draw an energy diagram associated with energy level change in a Bohr model
(ex. Figure 7.11B, P.297)
• Explain the wave-particle duality of matter and energy
• Calculate the de Broglie wavelength of any moving matter
• Explain the Heisenberg’s uncertainty principle and the resulting conclusion for
an electron
• Explain what ϕ and ϕ2 stands for in the Schrödinger equation/ quantum
mechanical model of atom
• Explain how the electron density diagram leads to the radial probability
distribution plot, and how we use that to determine the electron cloud
depictions/probability contour
• Explain why electrons of the quantum mechanical model of an atom doesn’t ‘fall’
into the nucleus
• Define the 3 quantum numbers for an orbital and determine what is an allowable
quantum number based on the definitions of n, l and ml, as well as identify the
orbital corresponding to the 3 quantum numbers
• Draw the shape of an s or p orbital (1s, 2s, 2p, 3p) and identify the shape of
other orbitals
• Explain how planar and radial nodes affect the shape of orbitals
For example test questions:
See Dr. Woodbury’s F2014 Practice Exam 2, available at:
https://sites.google.com/site/woodburychem1a/practice-exams-1
FYI- The key is available on the same site under: Practice Exam 2 Key
For more practice questions, read over every example problem in the chapters.