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Chapter 10 - Gasses - Coggle Diagram
Chapter 10 - Gasses
10.3 The Gas Laws
Boyle's Law
PV = k
P1V1 = P1V2
Pressure - Volume Relationship
Charles’s Law
Temperature - Volume Relationship
V/T = k
V1/T1 = V2/T2
Avogadro’s Law
Molar Quantity - Volume Relationship
1 mole of a gas had a volume of 22.4L at STP.
k = 22.4L/mol when at STP
Combined Gas Law
PV/nT = k
P1V1/n1T1 = P2V2/n2T2
10.4-10.5 The Ideal Gas Equation
PV = nRT
At STP R can be calculated
using Avogadro's Law
R = 62.36 L torr/mol K
R = 0.08206 L atm/mol K
However sometimes we need to use Density
PM = dRT
10.1-10.2 Characteristics of Gases and Pressure
Qualities of gasses
expand to fill their containers
are highly compressible (can be reduced in volume, thereby increasing their pressure)
have extremely low densities
Properties of Gasses
Pressure (P) - can be measured in atmospheres (atm), millimeters mercury (mmHg), torr, Pascals (Pa), or bars
Volume (V) - using measured in L or mL
Temperature (T) - measured in Kelvin (K) (when used in the mathematical equations)
Quantity (n) - measured in moles (mol)
10.6 Gas Mixtures and Partial Pressures
Dalton’s Law of Partial Pressures
PTotal = P1 + P2 + ... Pn
Mole fraction (X)
(n1/ntotal) = X
X = (n1/ntotal) = (P1/Ptotal)
P1 = X1PT
10.7 The Kinetic Molecular Theory of Gases (KMT)
KMT
Gases consist of large numbers of molecules that are in continuous, random motion.
The combined volume of all the molecules of the gas is negligible relative to the total volume in which the gas is contained.
Attractive and repulsive forces between gas molecules are negligible (due to Coulomb’s law and the relatively large distance between molecules compared to liquids and solids).
Energy can be transferred between molecules during collisions, but the average kinetic energy (of the molecules does not change with time, as long as the temperature of the gas remains constant.
The average kinetic energy of the molecules is directly proportional to the absolute temperature.
Maxwell-Boltzmann Distribution
10.8 Molecular Effusion and Diffusion
As molecular weights decrease, the average molecular speed increases
This phenomenon affects effusion, the escape of molecules through a tiny space along with diffusion, the spread of molecules throughout another substance.
10.9 Real Gases: Deviations from Ideal Behavior
The ideal gas law and KMT neatly describe the behavior of gases but in reality, gases are not ideal - they are what we call real gases.
However, deviations from these theories are not substantial unless:
Gases are at high pressure. Real gases do not behave ideally at high pressures.
Gases are at low temperatures close to where they condense to liquids.