Gases Flashcards
Kinetic molecular theory
five postulates that can derive the ideal gas laws
Postulate one
particles of a gas are in constant motion and collide with both one another and the container
Postulate two
the gas is mostly empty sapce
Postulate three
pressure is exerted when the particles hit the sides of the container
Postulate four
we assume that the particles do not interact with each other
Postulate five
-average kinetic energy is proportional to the temperature
-temp higher then particles move faster
Ideal gas
-an imaginary gas that perfectly fits all the assumptions of the kinetic molecular theory
-High temps=lower pressure
why have real gases
bc non-imaginary gases take up some space and have a tiny amount of attraction they are not ideal
Facts about ideal gases
-the volume is negligible
-no loss of energy between collisions
-no attractive or repulsive forces between gas molecules
-g particles are in constant random motion
-the pressure is caused by collision on the wall
-temp of g particles depends on their kinetic energy
things about real gases
-a real gas does not behave correctly according to the kinetic molecular t.
-the deviate more if there is high pressure or low temp
Pressure (what is it)
force per unit on an area
Gas pressure
caused by the collisions between gas particles and the sides of the container
Things that don’t affect the pressure
-mass of the particles
-size of the particles
Things that do affect the pressure
-number of particles
-moles
This is your reminder
study the mercury thing in your notes
other units of pressure
torr- same things as mmHg
atm- the exact amount of pressure in the atm at sea level 0C
pa- pascal 1n of force per square meter of area
order of pressures
1atm = 760mmHg = 760torr = 101.32kPa
Formula for farenhiet and celcuis
F=(1.8)C+32
Formula for kelvin
K=C+273.15
Kelvin temp scale
-used the principles that gases shrink when they cool
-using that he determined absolute zero where the gas would have no volume (no motion) 273.15
Charles law
- he discovered that O,N, H, CO2, and air expand predictably when heated
-says when pressure is held constant, volume is directly proportional to temp
Charles law formula
V1 over T1 = V2 over T2
Charles law simples
directly related, (look at graph) constant is p,
Boyles law
-Robert Boyle discovered when temperature is held constant, volume is inversely related to pressure
-when temp is held constant, volume is inversely related to pressure
