In which process is a solid substance volatilised by heating and the vapour is condensed back to the solid at a cold surface?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. Sublimation.
The process in which a solid substance is volatilized by heating and then the vapor is condensed back to the solid at a cold surface is known as sublimation. During sublimation, the solid directly transitions to the gaseous phase without passing through the liquid state. When the vapor comes into contact with a cold surface, it undergoes condensation and reverts to its solid form. This process is commonly used for purifying substances and in applications such as freeze-drying.