P1 - Condensation & Evaporation

Question 1

Describe the process of condensation

Answer 1

When a gas cools, the particles in the gas slow down and lose kinetic energy meaning the attractive forces between the particles pull them closer together

Question 2

What is evaporation?

Answer 2

When a liquid turns to a gas

Question 3

Describe evaporation

Answer 3

If particles are travelling in the right direction and are travelling fast enough to overcome the attractive forces of other particles in the liquid, these particles near the surface of the liquid can escape and become gas particles

Question 4

Describe the “cooling effect” of evaporation

Answer 4

The fastest particles with the most kinetic energy are most likely to evaporate and when they do, the average kinetic energy of the remaining particles decreases meaning that the remaining liquid cools

Question 5

Give 4 things that would increase the rate of evaporation and explain why

Answer 5

Higher temperature (more particles have enough energy to escape)

Lower density (forces between particles are weaker so it easier for particles to escape)

Larger surface area (more particles close to surface so that they can escape)

Airflow over the liquid is greater (the lower the concentration of an evaporating substance already in the air it’s evaporating into, the higher the rate of evaporation, a larger airflow means the air around the liquid is replaced more quickly)

Question 6

Give 4 things that would increase the rate of condensation

Answer 6

Temperature of the gas is lower (average particle energy is lower)

Airflow is less (the concentration of the substance in the air is higher so the rate of condensation is higher)

Temperature of the surface the gas touches is lower

Density is higher (attractive forces between particles is higher)

Question 7

What is condensation?

Answer 7

When a gas turns to a liquid