Ideal Gas Law
PV=nRT
Kinetic Molecular Theory
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1. Gases have low density
2. Gases have elastic collisions
3. Gases have continuous random motion.
4. Gases have no attraction or repulsion
5. Kinetic energy is proportional to
temperature.
Properties of Gases
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Pressure (P)
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Volume (V)
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The amount of space occupied by a gas
Temperature (T)
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Force of gas particles hitting the sides of their
container
The Kinetic Energy of gas molecules
Mols (n)
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The amount of gas molecules in a certain mass
Ideal Gas Law
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“the mathematical relationship among pressure,
volume, temperature, and the number of moles of a
gas”
What are the observable relationships between
these properties?
Pressure and Temperature
Pressure and Volume
Pressure and moles
Volume and Temperature
Volume and moles
Temperature and moles
Partial Gas Laws
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Boyle’s Law
V=k/P
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V : 1/P
Charle’s Law
V = kT
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V:T
Gay-Lussac’s Law
P=kT
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P:T
Avogadro’s Law
Standard Molar volume
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V:n
Ideal Gas Law
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V : 1/P
V:T
V:n
V : nT/P
V = constant * nT/P
PV = constant * nT
Constant = R
PV = nRT
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Units: (for this class)
V must be in Liters
P must be in atm
T must be in Kelvin
n is always mols
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Ideal Gas Constant = R
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0.0821(L*atm) / (mol * K)
Ideal Gas Law Example
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How many moles of gas are in 4.6 L of gas at
56kPa and 34oC?
Convert all units to the right units
Volume: 4.6 L is in correct units
Pressure: 56 kPa x (1atm/101.3kPa) = 0.55
atm
Temperature: 34oC + 273 = 307K
Write Ideal Gas Law Equation
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PV = nRT
Ideal Gas Law Example
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How many moles of gas are in 4.6 L of gas at
56Pa and 34oC?
PV = nRT
Solve for unknown
n = PV / (RT)
Plug in numbers
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n =(0.55 atm * 4.6 L) / (0.0821 * 307K)= 0.10mols
Simulation
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http://www.chem.ufl.edu/~itl/2045/MH_sims/g
as_sim.html