During the lyophilisation (freeze-drying) of a pharmaceutical vaccine, water is first frozen to a solid state. The surrounding pressure is then significantly reduced, and the solid ice is heated slightly, causing it to transition directly into water vapour. This vapour is subsequently collected on a cold condenser, where it converts directly back into solid ice.
What are the correct scientific terms for the phase transition of water from solid to gas, and from gas to solid, respectively?
Sublimation and condensation
Evaporation and condensation
Sublimation and deposition
Evaporation and deposition
84 exam-style questions on Edexcel GCSE Chemistry 3.1 States of matter, covering 3.1.1 The three states of matter and changes of state. Each one has a worked solution and a mark scheme showing where the marks go.