(a) Efflorescence is the property of some substances to lose wholly, or partly their water of crystallization when their crystals are exposed to dry air even for a short time.
Examples are: Washing soda, Glauber's salt , Epsom salt
(b) Certain water - soluble substances, when exposed to the atmosphere at ordinary temperature, absorb moisture from the atmospheric air to become moist and ultimately dissolve in the absorbed water, forming a saturated solution.
For example: Caustic soda, Caustic potash
