Patricle Theory Flashcards
What is gas pressure due to?
It is due to particles colliding with a surface
1 when gas is in a container the gas particles bounce off the walls as they move at high speeds
2 this creates pushing force on walls - called gas pressure
3amount of pressure depends on temperature and space inside the container
How do you increase gas pressure?
Increase temperature making particles move faster with 2 effects:
1 hit the walls harder
2 hit more often
Both increase pressure
Pressure increases with temperature only if volume remains the same
Reducing volume increases pressure -particles squashed into smaller space will hit walls more often
Examples of gas pressure
Car tyre pressure is higher at the end of a journey than the beginning as tyres warm up as they are used
Squeeze a full balloon, its volume gets smaller so same number of particles is crowded into smaller space - more squeezing, less space, more pressure until bursts with particles flying out with a bang
What is diffusion?
Particles spreading out from area of higher concentration to an area of lower concentration
Example of diffusion
A smell spreading through a room
Diffusion is slowed as smell particles bump into air particles stopping and send them in different directions
Like a blindfold race
Explain diffusion in liquids?
Diffusion happens when particles can move around each other - in liquids as well as gases e.g. Ink in a bowl of water slowly spreads
It is slower in liquids than gas because particles in liquid move more slowly and there are more particles to bump into
Experiment with diffusion
Ammonia gas in a test tube meets hydrogen chloride gas
Makes white smoke because particles move randomly
It turns to white smoke when they mix
Doesn’t happen in middle of test tube because ammonia diffuse faster than hydrogen chloride
