Question

What are deliquescent salts?

Answer 1

Hint : Deliquescence is a property or phenomenon of salts around water molecules. The presence of moisture around these ionic compounds brings significant changes in their solubility that allows these salts to gather the water molecules around them.

Complete Step By Step Answer:
Salts are ionic compounds formed as a result of neutralization reaction between an acid and a base. These salts are composed of strong electrostatic forces of attraction.
Deliquescent salts show a unique characteristic around water molecules. These are the salts that tend to absorb the moisture present in the atmosphere around them resulting in the dissolution of the salt.
The process of deliquescence is observed only when the vapour pressure of the solution being formed (by absorbing moisture from the atmosphere) from the salt is less as compared to the partial vapour pressure of the water vapour present in the surroundings.
A humid condition leads to an excess of water vapour in the atmosphere making its partial pressure exceptionally high due to which all salts become deliquescent in a humid atmosphere provided that the salts have good enough solubility in water.
Thus deliquescent salts are moisture absorbing salts that form a solution by simply absorbing the water vapours from the atmosphere.
Examples of deliquescent salts include ammonium chloride, sodium nitrate and calcium chloride.
Calcinated calcium chloride is known to settle road dust. This property is a consequence of deliquescence of calcium chloride.

Note :
Deliquescent salts are capable of dissolving themselves by simply absorbing the moisture around them. This property is a little different from being hygroscopic that it involves absorbing moisture but not up to the point of forming a solution.