Behavior of Gases
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Transcript of Behavior of Gases
Behavior of Gases
Kinetic Theory• Gases are composed of SMALL,
SEPARATE particles called MOLECULES.
• Gas molecules are in CONSTANT MOTION
• All COLLISIONS between particles are PERFECTLY ELEASTIC
• The MOLECULES of a gas display no ATTRACTION or REPULSION for one another.
Kinetic Theory
• The AVERAGE KINETIC ENERGY of the molecules is DIRECTLY PROPORTIONAL to the KELVIN temperature of the gas.
Ideal GasGas whose BEHAVIOR conforms to
the KINETIC THEORY -it is THEORETICAL.
Real GasParticles in a real gas…
Have their own volumeAttract each other
Gas behavior is most ideal…At low pressuresAt high temperaturesIn nonpolar atoms/molecules
Characteristics of Gases Gases expand to fill any container
Random motion, no attraction
Gases are fluids (like liquids)
No attraction
Gases have very low densities
No volume = lots of empty space
Gases can be compressed
No volume = lots of space
Gases undergo diffusion & effusion
Random motion
Gas Pressure:
Pressure = FORCE ÷ AREA = ____ atm
Atmospheric Pressure - the PRESSURE the earth’s ATMOSPHERE exerts due to its WEIGHT.
Barometer: Instrument used to measure �ATMOSPHERIC PRESSURE Invented by � TORRICALLI
Key Units101.325 kPa (kilopascal)
1 atm
760 mm Hg
760 torr
14.7 psi
101.3 kPa = 1 atm = 760 torr = 760 mm Hg
Standard Temperature & PressureStandard Temperature & Pressure
0°C 273 K
1 atm 101.325 kPa-OR-
STP
• Always use absolute temperature (Kelvin) when working with gases.
ºF
ºC
K
-459 32 212
-273 0 100
0 273 373
32FC 95 K = ºC + 273
Temperature