EFFLORESCENT, HYGROSCOPIC , DELIQUESCENCE , EFFLORESCENCE SUBSTANCE - DEFINITION
Some Important Characters of Compounds
EFFLORESCENT
SUBSTANCE - DEFINITION
An efflorescent substance is a chemical which has water associated
with its molecules, and which, when exposed to air, loses this water through
evaporation. A common example of this phenomenon is the drying of cement.
HYGROSCOPIC
SUBSTANCE - DEFINITION
This is when substances absorb water from air, but not enough to
form solutions. Examples of such substances include CaO,NaNO3,NaCl, sucrose
and CuO. Also, certain liquid substances absorb water from the air to get diluted,
these are also regarded as being hygroscopic. Example, conc. H2SO4 and conc. HCl. lf a
hydroscopic substance absorbs so much moisture that an aqueous solution is
formed, the substance becomes deliquescent.
DEFINITION OF
DELIQUESCENCE - DEFINITION
Deliquescence, the process by which a
substance absorbs moisture from the atmosphere until it dissolves in the
absorbed water and forms a solution.
Example are solid NaOH, CaCl2, CaCl2.6H2O
DEFINITION OF
EFFLORESCENCE - DEFINITION
Efflorescence, spontaneous loss of water
by a hydrated salt, which occurs when the aqueous vapor pressure of the
hydrate is greater than the partial pressure of the water vapor in the
air.
Examples are Na2SO4.10H2O, Na2CO3.10H2O and FeSO4.7H2O
