state changes

When does a substance absorb thermal energy without increasing in temperature?

When the substance is changing state

What is latent heat

The thermal energy transferred to or from a sample during a state change

When does latent heat of fusion occur?

Melting/freezing

When does latent heat of vaporisation occur?

Boiling/condensing

Latent heat of impure substance

Sample of impure substance does not remain at a constant temperature when changing state. The latent heat is absorbed or released over a range of temperatures

Specific latent heat formula (L)

L = E/m

Calculation when you are given a situation where a substances temperature rises, then a state change occurs

The energy transferred will be in two components:

• energy required to raise the temperature

• The energy required to change the state

These can be calculated using specific heat capacity and specific latent heat of substance . Total energy is the sum