Question

Give technical terms for the following.

The process by which a substance changes from the solid state to the gaseous state directly, without forming the liquid state.

Answer 1

1. When a substance changes from the solid-state to the vapor state without forming the liquid state, then it is called sublimation.
2. Sublimation is a type of physical change and reversible change.
3. Sublimation is also a reversible change, and the substance can be converted back to the original form by changing the reaction condition.
4. Example of substance that shows sublimation is Camphor, naphthalene, Iodine (I), dry ice (CO₂), and ammonium chloride (${\mathrm{NH}}_4\mathrm{Cl}$).