kinetic theory Flashcards
what is outward pressure
gas pressure is caused by the collisions between the particles and their container. outward pressure is usually greater than normal atmospheric pressure outside the container
what is atmospheric pressure measured in
one bar
how does pressure increase
when the temperature increased, the gas particles move faster and the collisions became more frequent. This means that pressure also increases.
relate the change in volume of a gas to the change in pressure
because there has been a decrease in volume the particles will collide more frequently with the walls of the container. Each time they collide with the walls, the exert a force on them. More collisions mean more force so pressure will increase
what is the constant equal to
pressure x volume
what is evaporation and how does it link to cooling
the particles in a liquid have different energies. some will have enough energy to escape from a liquid and become a gas. the remaining particles in the liquid have a lower average kinetic energy than before, so the liquid cools down as evaporation happens
what is the difference between boiling and evaporation
a liquid boils at its boiling point - all of the liquid reaches this temp and gradually turns into a gas. Evaporation happens at a lower temp, below the boiling point
how does increased temp increase rate of evaporation
heat gives particles in a liquid more kinetic energy and then they therefore have more chance to escape from the surface and evaporate
increased surface area can increase the rate of evaporation because
more particles in the liquid are exposed to the surface so more can evaporate at once
how does airflow affect evaporation
as the wind blows, it sweeps the airborne water particles that are in the air. The humidity of the air in the region of evaporation is reduced, which allows more water molecules to dissipate in the air.
