Gas Laws Flashcards
The kinetic theory of matter
1) all matter is made up of tiny particles called molecules
2) the molecules are in a constant state of rapid, random motion
3) the higher the temperature, the more energy the molecules posses so the faster they move
Pressure acts in
All directions
Evidence for the kinetic theory of matter is given by
Diffusion and Brownian motion
Diffusion
When one substance gradually spreads through another substance.
(E.g. Perfume diffusing across the room if the top is left off the bottle, mixing win a drop of coloured dye placed in a glass of water)
Brownian motion
If a cell of air containing some smoke is illuminated and viewed under a microscope, the smoke particles can be seen moving about randomly in all directions with a jerky motion
The viewing of the Brownian motion of a smoke particle in a glass cell
IThe air molecules collide with smoke particles, which causes them to travel in random directions.
The viewing of the Brownian motion of a smoke particle in a glass cell was first observed using
Pollen grains in water
Boyles law
For a fixed mass of an ideal has at a constant temperature, if the volume of the gas is decreased, the pressure exerted by the gas will increase.
The product of the pressure of the gas and the volume of the gas is a constant.
The pressure exerted by a gas
in a gas there are no forces of attraction between the molecules, and the molecules are free to move around rapidly and randomly, colliding with the walls of any container around them.
As the molecules collide with the walls of the container, they exert a force and hence a pressure on the walls of the container
if the volume if the gas is decreased
the pressure exerted by the gas increases, because the same number of molecules as before collide with a smaller area
if the gas is confined to a container and heated
the molecules with posses a greater average kinetic energy, as a result their speed will increase and the gas molecules will:
collide more frequently with the walls of the container
exert a greater force on the walls during each collision
kelvin scale
0 degress c= -273K
if you increase the kelvin temp
the speed and pressure of the molecules increase
if you double the kelvin temp
the ke of the molecules also double
two assumptions you make in p1v1=p2v2
there is no change in temp
there is a constant mass
