State Changes

Question 1

Changes of state are

Answer 1

physical changes that are reversible
These changes do not change the chemical properties or chemical makeup of the substances involved

Question 2

Vaporisation includes

Answer 2

evaporation and boiling

Question 3

Evaporation involves the change of liquid to gas, but unlike boiling, evaporation occurs only

Answer 3

at the surface and takes place at temperatures below the boiling point

Question 4

Boiling occurs

Answer 4

at a specific temperature and takes place when the vapour pressure reaches the external atmospheric pressure

Question 5

What is sublimation

Answer 5

Some substances can change directly from solid to gas, or from gas to solid, without becoming a liquid in between. This is called sublimation

Question 6

What is Deposition

Answer 6

gas to a solid

Question 7

The relationship between temperature and energy during state changes

Answer 7

Between 1 & 2, the particles are vibrating and gaining kinetic energy and the temperature rises

Between 2 & 3, all the energy goes into breaking bonds – there is no increase in kinetic energy or temperature

Between 3 & 4, the particles are moving around and gaining in kinetic energy

Between 4 & 5, the substance is boiling, so bonds are breaking and there is no increase in kinetic energy or temperature

From 5 & 6, the particles are moving around rapidly and increasing in kinetic energy