Question

Sodium chloride was used as an important symbol in our freedom struggle. Mahatma Gandhi and his followers did Dandi march in order to stop the British government from increasing the price of common salt used daily by Indian people.

(a) What is rock salt? How is it formed?

Answer 1

• Rock salt is also known as halite.
• It is salt in its natural form and made up of sodium chloride which contains dissolved ${\mathrm{Na}}^{+}$ and ${\mathrm{Cl}}^{-}$ ions.
• Its chemical formula is $\mathrm{NaCl}$
• It is formed by the evaporation of salty water (such as seawater) which contains dissolved ${\mathrm{Na}}^{+}$and ${\mathrm{Cl}}^{-}$ ions.
• Rock salt deposits can be found in ringing dry lake beds, inland marginal seas, and enclosed bays and estuaries in arid regions of the world.