Chemistry Equations

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Chemistry Equations Table

Boyle’s Law and Curve At constant T—> PV=PV
Charles’ Law and Curve At constant P V/T=V/T
Dalton’s Partial Pressure Law Ptotal= ∑XiPtotalPartial pressure= Mole fraction x P total

P total= Sum of all the partial pressures
Faraday’s Law I x time= n x FF= 100000 (10⁴)Coulombs/mole e
n= number moles of electrons

Plates metal at the cathode (mass goes up)
Corodes substance at the anode (mass goes down)
Graham’s Law for Diffusion/Effusion Rate 1/ Rate 2= √M2/M1
Ideal Gas Law PV= nRTR= 8.314
P in Pascals
V in m³
T in K
Van der Waal’s equation Deviation from ideal gas behavior

P (pressure)= [nRT/ V- nb] – [n²a/V²]
Essentially this is P= repulsion- attraction

– b= bounce, the greater b is… more repulsion
– a= attraction, the greater a is the less pressure there is

Free Energy

ΔG equation (Free energy equation) ΔG= ΔH- TΔS

ΔG=ΔG° + RTlnQ
ΔG – Free energy that is available to do work


Avogadro’s number for a mole6.02 x 10^23 molecules
# moles# moles = mass in grams/ molecular weight
MolarityMolarity = # moles of solute/ # of liters in solution


Phase Changes ΔH fusion= – ΔH freezing
ΔH vaporization= – ΔH condensation
ΔH sublimation= – ΔH deposition
Phase changes with MOST energy change ΔH fusion +Δ H vaporization= ΔH sublimation– Sublimation and Deposition= greatest enthalpy change
– Vaporization and Condesnation= 2nd largest
– Fusion and Freezing has LOWEST enthalpy change


Osmotic pressure π= MiRTM= molarity
R= 8.314
T in Kelvin


Rate Law rate= k [X]ⁿ[Y]ⁿ– Stoich coeffs are NEVER the exponents of a rxn UNLESS it is the ELEMENTARY rxn!
– Always need to divide
– Rate law of rxn is rate law of RDS
Arrhenius Equationk= Ae ^ (-Ea/ RT)
A is a constant
Low Ea means High T–> large K and FASTER rxn!

e to a neg number means a decimal
e to a larger number gives a larger number


Ksp Calculations Ksp for Ag₂SO₄= [Ag+]²[SO₄]

Ksp= [2x]²[x]= 4x³

MAKE sure to square ALL NUMBERS!
Ex: 3x³= 27x³
Ksp= Solubility product constant
Changes with TEMP/ Particle Size/ Polarity

More positive the Ksp–> the more product will dissolve in solution at equilibrium
Henry’s Law Solute concentration= kPsolutePsolute= partial pressure of solute at solution’s surface

Concentration of solute in solution is directly proportional to partial pressure of solute just above solution surface


Boiling Point Elevation ΔTb= Kb(i)m m= molality
Freezing Point Depression ΔTf=Kf(i)m m= molality


First Law of Thermodynamics ΔE= Q + WConservation of energy
Change in total INTERNAL energy of system is equal to contributions from heat and work
Second Law of Thermodynamics ΔS≥ q/ TIsolated system will increase in entropy over time
– Open system can decrease in entropy but at the expense of greater increase in entropy of surroundings
In short- total entropy of universe is always increasing
– REAL processes are never reversible–> entropy change is always greater than the heat transfer over temp