Sublimation

What is Sublimation?

It is a process where a solid directly converts into its gas phase without going into liquid state .

Example

Solids like Ammonium chloride, Naphthalene,Camphor and Anthracene undergo Sublimation.

When we heat them they convert directly into gases without first converting into liquid

Hence, to separate a mixture having a sublimable and non-sublimable component , we use the method of sublimation.

How to Separate a Mixture of Salt and Camphor?

In a mixture of Salt and Camphor,

Camphor 

• Sublimes on heating
• Hence it is a sublimable component

Common salt (Sodium Chloride) 

• Does not undergo sublimation
• It is a non sublimable component.
  
  

Procedure

1. Take a mixture of salt and camphor in a china dish
2. Place an inverted funnel over it
3. Close the end of the funnel with a cotton plug
4. Now heat the mixture
   
   

• On heating, camphor undergoes sublimation (converts into vapours)
  These vapors solidify again on the surface of the funnel
• However salt does not undergo sublimation and remains on the china dish