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Planck relation (frequency)
E = hƒ
h = 6.626×10^-34 m²*kg/s
angular momentum on an electron (bohr model)
L = nh/2π
energy of an electron (bohr model)
E = - RH/n²
Planck relation (wavelength)
E = hc/λ
Energy of electron transition (Bohr model)
E = RH[1/ni² - 1/nf²]
maximum number of electrons within a shell
2n²
max number of electrons within a subshell
4l+ 2
l = n-1 (between 0 and n-1)
Dipole moment
p = qd
Formal charge
V- Nnonbonding - 1/2 Nbonding
Valence electrons -dots - sticks
moles from mass
Moles = mass of a sample/ Molar mass
gram equivalent weight
GEW = molar mass / n
(where n = number of equivalent ions of desired)
equivalents from mass
equivalents = Mass of compound/ gram equivalent weight
molarity from normality
Molarity = normality / n
percent composition
% composition = mass of element in formula/ molar mass x 100%
percent yield
% yield = actual yield/ theoretical yield x 100 %
avogadro’s number
6.022 × 10^(23) mol ^-1
normality
N = equivalents/ L
equivalents = Mass of compounds (g)/ gram equivalent weight (g)
1 mole of any ideal gas at STP =
22.4 L
Collision theory
rate = Z x ƒ
Z = total number of collision per second
f = fraction of collisions that are effective
rate = rate of rxn
Arrhenius equation
k = Ae^(-Ea/RT)
where k = reaction rate constant
A = Frequency factor
Ea = activation energy (J/mol)
R = universal gas constant = 8.314 J/mol *K
T = Abs temp (Kelvin)
(e): Euler's number, a mathematical constant approximately equal to 2.718.
universal gas constant
R = 8.314 J/mol *K
definition of rate
rate = - ∆ [A] / a∆t = - ∆[B]/b∆t = ∆C/c∆t = ∆D/d∆t
when aA+bB → cC + dD
rate law
rate = k[A]x[B]y
when aA+bB → cC + dD
Radioactive decay
[A]t = [A]0e^-kt
([A]t): The concentration of reactant (A) at a specific time ((t))
([A]0): The initial concentration of reactant (A) (at time zero, before the reaction starts).
(e): Euler's number, a mathematical constant approximately equal to 2.718.
k = The first-order rate constant. For a first-order reaction, its unit is always s-1(per second) or another unit of reciprocal time
t = elapsed time
Q < Keq; ∆G < 0
reaction proceeds in forward direction
Q = Keq ; ∆G = 0
rxn is in dynamic equilibrium
Q > Keq ∆G > 0
reaction proceeds in reverse direction
Keq
ratio of products to reactants at equilibrium
Q reaction quotient
calculated value that relates the reactant and product concentrations at any givnen time during a reaction
Keq >1
products are present in greater concentration at equilibrium
Keq ≈ 1
products and reactants are both present at equilibrium at reasonably similar levels
Keq <1
reactants are present in greater concentrations at equilibrium
Keq« 1
amount of reactants that have been converted to products can be considered negligible in comparison to the initial concentration of reactans
3 types of stress to a system
pressure and volume, temperature, and changes in concentration
increasing concentration of reactants or decreasing concentration of products will shift the rxn to
right
increasing the concentration of products or decreasing concentration of reactants will shift rxn
left
increasing pressure on a gaseous system (decreasing its volume) will shift the reaction toward side with
fewer moles of gas
decreasing pressure on a gaseous system, increasing volume will shift rxn toward
side with more moles of gas
increasing temp of an endothermic rxn or decreasing the temp of an exothermic rxn will shift rxn to
right
decreasing temp of an endothermic rxn or increasing the temp of an exothermic rxn will shift rxn to
left
kinetic product
higher in free energy, form at lower temps; fast products
thermodynamic productws
lower in free energy than kinetic products, more stable, proceed more slowly, more spontaneous
Keq for aA+bB → cC + dD
[C]c[D]d/ [A]a[B]b
reaction quotient Qc for aA+bB → cC + dD
Qc = [C]c[D]d/ [A]a[B]b
First law of thermodynamics
∆U = Q - W
where
∆U = change in internal energy
Q = heat energy
W = work done
+Q vs -Q
(+Q) = Heat is absorbed by the system (endothermic).
(-Q) = Heat is released by the system (exothermic)
+W vs -W
(+W) = Work is done by the system on the surroundings (e.g., a gas expanding). Energy leaves the system, which is why it is subtracted.
(-W) = Work is done on the system by the surroundings (e.g., a gas being compressed). The two minus signs cancel out ((-(-W) = +W)), adding energy to the system.
heat transfer ( no phase change)
q = mc∆T
q = heat energy (joules or cal) +q = absorbed heat -q= released heat
m= mass (g) or kg
c = specific heat capacity (J*(g *°C)
∆T= Tf - T0 ( Celsius or K)
heat transfer during phase change
q =mL
q = heat transer
m = mass
L = latent heat (J/g)
Generalized enthalpy of reaction
∆Hrxn = Hproducts - Hreactants
+ means
-means exothermic
Standard enthalpy of reaction
∆H°rxn = ∑H°f,products -∑H°f,reactants = total energy absorbed - total energy released
entropy
∆S = Qrev/T ;(J/K)
+∆S = more disordered
-∆S = more ordered
Qrev= reversible heat (J)
T = temp (K)
second law of thermodynamics
∆Suniverse = ∆Ssystem + ∆Ssurroundings > 0
Standard entropy of rxn
∆S°rxn = ∑∆S°f,products+ ∑∆S°f,reactants
Gibbs free energy
∆G = ∆H -T∆S
Standard Gibbs Free energy of rxn
∆G°rxn = ∑∆G°f,products- ∑∆G°f,reactants
Standard gibbs free energy from equilibrium constant
∆G°rxn = -RT ln Keq
R = 8.314 J/(mol*K)
T = temp K
Keq = equilibrium constant
gibbs free energy from reaction quotient
∆Grxn = ∆G°rxn + RT ln Q = RT ln Q/ Keq
if Q/Keq is less than one Q<Keq nat ln will be negative and free energy will be negative
if Q/Kee is greater than one Q>Keq then positive and free energy will be positive
if equal reaction will be ln 1 = 0
standard conditions
298 K, 1 atm, 1 M
fusion
melting
freezing
crystallization or solidification
vaporization
evaporation or boiling
condensation
gas to a liquid
Sublimation
solid to gas
deposition
gas to solid
+∆H + ∆S
spontaneous at Hi T
+∆H - ∆S
nonspontaneous at all T
-∆H + ∆S
spontaneous at all T
-∆H -∆S
spontaneous at low T
ideal gas law
PV = nRT
P = pressure (N/m² Pa)
V= VOLUME (m³)
n = moles (mol)
R = ideal gas (8.314 J/(mol*K) use (0.08206 L*atm/Mol*K if P in atm and V in L)
T = temp (K)
1 atm =
101.3kPA
Density of a gas
ρ=m/V = PM/RT
m = mass
V= volume
P = pressure
M = molarmass
R = ideal gas = 0.08026 L*atm/ (mol*K)
T = temp
density = mass over volume
Combined gas law
P1V1/T1 = P2V2/T2
P = Pressure
V = volume
T = temp
avogadro’s principle
n/V = k (constant)
n1/V1 = n2/V2
n= moles
V = volume
k = constant so just assume set equal
Boyle’s Law
PV = k or P1V1=P2V2
Pressure
Volume
k = constant
Charles’s law
V/T = k
k = constant
V = volume
T = temp (K)
Gay-Lussac’s law
P/T = k or P1/T1 = P2/T2
pressure
T in Kelvin
Dalton’s law total pressure from partial
PT = PA+PB+PC ….
DAlton’s law partial pressure from total pressure
PA = XAPT
Henry’s Law
[A] = kH x PA or [A]1/P1 = [A]2/P2
concentration of A = constant * pressure
avg kinetic energy of a gas
KE = 1/2mv² =3/2kBT
kB is boltzman constant = 1.38×10^-23 J/K
T in kelvin
root mean square speed
urms = sqrt√(3RT/M)
R = 8.314 J/(mol*K) J=kg*m²/s²
T = kelvin
M = molar mass (kg/mol)
Graham’s law
r1/r2 = sqrt√(M2/M1)
M = molar mas
r = rate of effusion for gas 1 and 2 (V/t volume per time)
van der Waals equation of state
(P + n²a/V²) (V-nb) = nRT
Pressure, Volume, moles, T in K, R= 0.08206 atm*L/(mol*K)
a = intermolecular attraction constant (L²*atm/mol²)
b= moleculr volume constant (L/mol)
% composition by mass
mass of solute/mass of solution * 100%
mole fraction
XA=moles of A/total moles of all species
molality
moles of solute/kilograms of solvent = m
Dilution formula
MiVi = MfVf
M= molarity
V = volume
solubility product constant
Ksp = [An+]m[Bm-]n
for AmBn ↔mAn+(aq) + nBm- (aq)
ion product
IP = [An+]m[Bm-]n
for AmBn ↔mAn+(aq) + nBm- (aq)
if IP< Ksp
solution is unsaturated, if more solute added it will dissolve
IP = Ksp
solution is saturated at equilibrium and no change in concentration
IP > Ksp
solution is super saturated, precipiatate will form
Raoult’s Law (vapor pressure depression)
PA= XAP°A
Xa= mole fraction
P°= pressure of pure
Pa is = pressure of solvent
boiling point elevation
∆Tb = iKbm
i = # of particles it will split into vant hoff
m = molality (mol/kg)
Kb = molal boiling point elevation constant
∆Tb = Tboiling solution - Tboiling solvent (how much higher from pure state)
freezing point depression
∆Tf= iKfm
m = molality (kg/mol)
i = vant hoff factor amount of particles splits into # , if no split = 1
Kf = fixed constant of freezing °C/m
∆Tf= Tfreezing pure - Tfreezing solvent
osmotic pressure
π= iMRT
(atms)
i = vant hott
M= molarity (mol/L)
R= 0.08206 L*atm/mol*K
T = temp in K
Hypochlorite
CLO-
CLO2-
chlorite