Condensation and Evaporation Flashcards
What in condensation?
When gases turn to liquids.
What happens when a gas cools?
The particles in the gas slow down and lose kinetic energy.
What forces in the gas pull the particles close together?
The attractive forces.
What must happen for condensation to occur?
If the temperature gets cold enough.
The gas particles get close enough together.
What does water vapour do in the air?
It condenses when it comes in contact with cold surfaces.
What is the steam you see rising from a boiling kettle?
Invisible water vapour condensing for form tiny water droplets as it spreads into cooler air.
What is evaporation?
When liquid turns to gas.
Th particles escape from the liquid.
The particles can evaporate from a liquid at what temperatures?
Temperatures that are much lower than the liquid’s boiling point.
The particles near the surface of the liquid do what?
Escape and become gas particles.
What must the particles in the liquid be doing to escape?
Travel in the right direction.
Travel fast enough to over come the attractive forces of the other particles in the liquid.
Fastest particles =
Most likely to escape the liquid.
When particles leave the liquid what happens?
The average speed and kinetic energy of the remaining particles decrease.
The decrease in the average particle energy means what?
The temperature of the remaining liquid falls.
Give an example of evaporation.
When you exercise you get hot so therefore sweat.
As the water evaporates off your body it cools you down.
Rates of condensation and evaporation can ____
Vary.
The rate of evaporation will be faster if what happens.
Name 4 things?
Temperature is higher.
Density is lower.
Surface area is larger.
Airflow over the liquid is greater.
In evaporation why is it good if the temperature is higher?
Average particle energy will be higher.
More particles will have enough energy to escape.
In evaporation why is it good if the density is lower?
Forces between the particles will be weaker.
Particles can overcome the forces and escape.
In evaporation why is it good if the surface area is larger?
More particles able to flow near the surface and escape the liquid.
In evaporation why is it good if the airflow over the liquid is greater?
Lower the concentration of an evaporating substance in the air its evaporating into, the higher the rate of evaporation .
What does a greater air flow mean?
Air above the liquid is replaced more quickly.
As concentration in the air is lower.
The rate of condensation will be faster when…
Name 4 things?
Temperature of the gas is lower.
Temperature of the surface the gas touches is lower.
Density is higher.
Airflow is less.
In condensation why is it good if the temperature of the gas is lower?
Average particle energy in gas is lower.
More particles slow down to clump together and fom liquid droplets.
In condensation why is it good if the density is higher?
Forces between particles will be stronger.
Few particles will have enough energy to overcome forces so will have to clump together and form a liquid.
In condensation why is it good if the airflow is less?
Concentration of the substances in the air will be higher.
Rate of condensation will be greater.
