Question

Differentiate between Deliquescence and Efflorescence.

Answer 1

Deliquescence	Efflorescence
Substances that absorb water when exposed to the atmosphere and become moist and ultimately form a solution are called Deliquescent substances and the phenomenon is called Deliquescence.	Substances that lose their water of crystallization when exposed to air are called Efflorescent substances and this phenomenon is called Efflorescence.
For example: $\mathrm{Sodium}\mathrm{Carbonate}\mathrm{Decahydrate}(\mathrm{Washing}\mathrm{Soda}){\mathrm{Na}}_2{\mathrm{CO}}_3.10{\mathrm{H}}_2\mathrm{O},\mathrm{Sodium}\mathrm{Carbonate}\mathrm{Decahydrate}{\mathrm{Na}}_2{\mathrm{SO}}_4.10{\mathrm{H}}_2\mathrm{O}$	For example: $\mathrm{Sodium}\mathrm{hydroxide}\mathrm{or}\mathrm{Caustic}\mathrm{Soda}\left(\mathrm{NaOH}\right),\mathrm{Magnesium}\mathrm{Chloride}\left({\mathrm{MgCl}}_2\right),\mathrm{Calcium}\mathrm{Chloride}\left({\mathrm{CaCl}}_2\right)$