Chemistry
Give reasons for the following :
(i) table salt becomes moist and sticky during the rainy season.
(ii) a white powder forms on the surface of washing soda crystals which are left exposed to the air.
Answer
(i) Table salt is not deliquescent but contains a small amount of calcium and magnesium chloride impurities which are deliquescent. Hence, the impurities absorb moisture from the atmosphere, thereby turning table salt sticky and wet especially during humid conditions.
(ii) Washing Soda is a efflorescent substance and so when it is exposed to the atmosphere, it loses it's moisture [water of crystallization] partly and changes into amorphous state. Hence, a white powder forms on the surface of washing soda crystals which are left exposed to the air.
Related Questions
Name one substance which is 'deliquescent'.
How does an increase in temperature affect :
(i) the solubility of NaCl
(ii) the solubility of CaSO4 in water ?Why is anhydrous CaCl2 used in a desiccator. Name one substance which is 'efflorescent'.
Name a salt
(a) which contains water of crystallization
(b) which does not contain.