Mention five hygroscopic substances, five deliquescent
substances and five efflorescent substances along with their uses in
daily life in detail.
Answers
HOPE THIS HELPS YOU :
(1) HYGROSCOPIC SUBSTANCES --
This is when substances absorb water from air, but not enough to form solutions. Examples : 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.
USES : Cellulose fibers (such as cotton and paper), sugar, caramel, honey, glycerol, ethanol, wood, methanol, sulfuric acid, many fertilizer chemicals, many salts (like calcium chloride, bases like sodium hydroxide etc.
(2) DELIQUESCENT SUBSTANCES --
Deliquescence, the process by which a substance absorbs moisture from the atmosphere until it dissolves in the absorbed water and forms a solution.
Examples : solid NaOH, CaCl2 , CaCl2.6H2O
USES : Sodium hydroxide, potassium hydroxide, ammonium chloride, gold(III) chloride, sodium nitrate, and calcium chloride. While table salt or sodium chloride (NaCl) may be deliquescent if the particles are small and the humidity is very high.
(3) EFFORESCENT SUBSTANCES --
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.
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 : Na2SO4.10H2O, Na2CO3.10H2O and FeSO4.7H2O
USES : Washing soda (Na2CO3·10H2O) , Glauber’s salt (Na2SO4·10H2O).
Thank You.