The Chemist's tools 9.1.7 - Changes of state


Students should:

  • Understand that the states of matter are linked to the temperature of the matter
  • Know the terms melting, fusing, boiling, vaporisation, solidifying, freezing, condensing.
  • Know that the kinetic energy available to particles is directly related to the temperature.
  • Know that energy is needed to break interparticular forces
  • Know that energy is released when bonds form between particles
  • Know the relationship between the Kelvin temperature scale and the Celsius temperature scale.


Matter: states and properties of matter.

Particle/kinetic theory, diffusion.

Pure and impure substances. Types of mixtures (solutions, oils, alloys, emulsions)

Separation techniques, including filtration, distillation [including crude oil - myp10], chromatography.


Measuring temperature. The absolute (Kelvin) and Celsius scales.

Experiment 4

Cooling/heating curves - The cooling curve of phenol


Data analysis


Changes of state

Enthalpy of fusion/solidification

Teacher's notes

Phenol is not a particularly nice substance and can cause burns if it comes into contact with the skin. The test tubes of phenol should be prepared in advance.

A sodium hydrogencarbonate solution can be kept handy to wash any spilt phenol.



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