Chem 1150 - Gases Lecture Notes

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Gas Pressure Equation

Gas Pressure: P = F / A

Ideal Gas Characteristics

1. The gas molecules do not attract or repeal each other.

2. The gas molecules take up a NEGLIGIBLE amount of space within a container

Ideal Gas Law

PV = nRT

P = pressure (atm)

V = Volume (L)

n = # of mols

R = Gas Constant (0.08206 L*atm/mol*K)
T = temperature (K)

Boyle’s Law

Pressure & Volume INVERSELY proportional if constant Temperature and Mols

P ∝ 1 / V

Charles’ Law

Volume and Temperature proportional at constant Pressure and Mols

V ∝ T

Avogadro’s Law

Amount of Gas (mols) and Volume proportional if constant Pressure and Temperature

n ∝ V

Combined Gas Law

P₁V₁/T₁ = P₂V₂/T₂

Alternate Ideal Gas Law

PM = dRT

P = atm

M = molar mass

d = density

R = gas constant\

T = temperature

Gases Stoichiometry - Solids

moles = (grams / Molar Mass)

Gases Stoichiometry - Liquid

moles = mols / volume

Gases Stoichiometry - Gas

moles = (PV / RT)

Dalton’s Law of Partial Pressures

Total Pressure = P₁ + P₂ + P₃ + …

Partial Pressure of a gas within a mixture

P_A = X_A * P_total
Mole Fraction (X_A) = moles A / total of gas moles in mixture

Kinetic Molecular Theory

μ = sqrt((3RT)/MM_kg)

R = 8.314 J/mol*K

T = Temperature (K)

MM_kg = Molar Mass of gas in kg/mol

The bigger the gas molecule the slower the average speed

Mean Free Path

Average distance between collisions for gas molecules

Van der Waals Equation

(P + an²/V²)(v - nb) = nRT

a & b are “correction factors” (constants dependent on the gas being examined)