changes of state

Question 1

what does a pure substance have?

Answer 1

A pure substance has a specific melting and boiling point

Question 2

when does boiling occur?

Answer 2

Boiling occurs throughout a substance at its boiling point.

Question 3

when does evaporation occur?

Answer 3

Evaporation occurs from the surface of the liquid below the boiling point.

Question 4

how are changes of state shown on a temperature time graph?

Answer 4

Changes of state are flat lines on a temperature time graph

Question 5

what happens as you increase the temperature?

Answer 5

Increasing the temperature increases the internal energy and allows a substance to change state

Question 6

what is specific latent heat of vaporisation?

Answer 6

Specific latent heat of vaporisation is the amount of energy needed to turn 1kg of a substance from liquid to a gas

Question 7

what is specific latent heat of fusion?

Answer 7

Specific latent heat of fusion is the amount of energy need to turn 1kg of a
substance from a solid to a liquid.