Equations Flashcards
Plank’s frequency relation
E = h(f or nu)
E=energy
h= Plank’s constant (6.63 x 10^-34 Js)
f=frequency
What equation is similar to Plank’s frequency relation?
c/v=wavelength x frequency (v or nu)
When would Plank’s frequency relation be used?
To calculate energy or frequency
Angular momentum equation
L=nh/2(pi)
n=principal quantum number
h=Plank’s constant
Plank’s constant
6.63 x 10^-34 Js
When would angular momentum of an electron around a hydrogen be used?
Quantized by higher principle number, higher momentum
Larger principle quantum numbers have higher momentum
Energy of an electron equation
E=-RH/n^2
When would the energy of an electron be important?
Energy of electron is directly proportional to the principle quantum number
Because of negative sign, larger number gets closer to zero, larger
Rydberg unit of energy
2.18 x 10^-18 J/electron
Avagadro’s number
6.02 x 10^23
Measure of things - usually measures a number of atoms within a mass number
1 mol=6.02 x 10^23 atoms= # amu
The units of a mol
Electromagnetic energy of a photon equation
E=hc/(wavelength) or
-RH[1/n^2-1/n^2]
Speed of light (c)
3 x 10^8 m/s
Max number of electrons in a shell
2n^2
Values of l
Subshell 0=s 1=p 2=d 3=f
Max number of electrons in a subshell
4l + 2
Max value of l
0 to n-1
ml
Orbital within subshell
Max electrons in a orbital
2e
Values of ml/orbitals per l
any l has 2l +1 values of ml
Orbitals/ml per principle number
n^2
Values of ms
+1/2, -1/2
How to determine which subshell is lower
n +1
If same, lower n will fill first
Values of ml
between -l and +l
Percent composition
All of them= 1
Each one’s mass number amount= given atomic weight
1 amt =
760 Torr = 760 mmHg = 101.325 kPa
STP
273 K
1 atm
For gas law calculations
Standard conditions
298 K
1 M
For entropy, enthalpy, Gibb’s free energy, and electromotive forces
Ideal gas law
PV=nRT
R
Ideal gas constant
8.21 x 10^-2 Latm/molK
or 8.314 J/molK
How much does 1 mol of ideal gas occupy?
22.4 L
Density equation
=m/V = PM/RT
Combined gas law
PV1/T1 = PV2/T2
When would the combined gas law be used?
When the moles stay constant, but need to find the other factor
How to find density from combined gas law?
Substitue V1= 22.4 L and use STP to compare to current
Then divide mass/new volume
How to find molar mass from combined gas law?
Used combined gas to find V at STP
Divide weight by newfound liter amount
Multiply g/L by ideal gas volume = g/mol
Density at STP x volume of one mol
Avagadro’s principle
n/V=k
n1/V1=n2/V2
k is a constant
Gibb’s free energy equation
Delta G= Delta H- TDelta(S)
Percent by mass
mass of solute/mass of solution x 100
Mole fraction
mol of A/mol of all species
Molarity
mol solute/L solution
p value=
m-0.n
Ka
[H3O=]{A-]/[HA]
Kb
[B+][OH-]/[BOH]
Faraday’s constant
10^5 C/mol e-
Electrodeposition equation
mol M=It/nF
n=oxidation state
Boyle’s Law
PV=k
PV=PV
Charles’s Law
V/T=k
V/T=V/T
Gay-Lussac’s Law
P/T=k
P1/T1=P2/T2
Dalton’s Law of Partial Pressures
Ptotal=PA + PB +PC …
Partial pressure equation
PA=XA(PT)
XA=mol of gas A/total moles of gas
Vapor pressure
[A]= kH x Pa [A]1/P1=[A]2/P2= kH
[A]=concentration
kH=Henry’s constant
PA=partial pressure of A
Average kinetic energy of a gas
KE=1/2mv^2=(3/2)kBT
kB=Boltzmann constant
Boltzmann constant (kB)
1.38 x 10^-23 J/KT
Root-mean-square speed (u rms)
u rms= Square root (3RT/M)
R=ideal gas constant
M=molar mass in kg/mol
R (Ideal gas constant)
8.314 J/Kmol
Graham’s law
r1/r2=Square root(M2/M1)
Ex. A gas that has a molar mass 4x of another, it will travel half as fast
Van der Waals Equation of State
(P +n^2a/V^2)(V-nb)=nRT
ab=constants for each gas
a constant
Corrects for attractive forces (smaller for smaller less polarizable molecules and largest for polar moleucles)
b constant
Corrects for volume of molecules due to size
Standard electromotive force (emf)
E(cell)=E(red,cathode)-E(red,anode)
Do you multiply cell potentials when coming up with net reactions?
No
Delta G and emf
Delta G= -nFEcell
n=mols of electrons exchanged
F=Faraday constant
Ecell=standard emf
Deviation from normal cell emf
Ecell=E(cell standard) - RT/nF (lnQ)
Q=reaction quotient
Simplified deviation from normal cell emf
E cell=E(cell standard) -0.0592/n(logQ)
Reaction quotient
Q=[C]^c[D]^d/[A]^a[B]^b
Lower case is number in front
Delta G equation
-RTlnKeq
Change in Free energy of electrochemical cell with varying concentration
Delta G= Delta G(standard) + RTlnQ
Rate law
k[A]^x[B]^y
Arrhenius equation
k=Ae^-Ea/RT
Radioactive decay
[A]t=[A]e^-kt
Concentration of Solution after dilution
MV=MV
Normality
mols solute/kg solvent
Boiling point depression expression
Delta(T)=iKbm
i=van’t Hoff factor=number of particles in which a compound dissociates (NaCl=2)
Kb=proportionality constant of the solvent
m=molality
Temperature in Kelvin
Density of water
1g/mL
Freezing point depression
Delta T f=iKfm
i=van t’Hoff
Kf=proportionality constant
m=molality
Temperature in Kelvin