It is also known as common salt or table salt. It is mainly obtained by the evaporation or sea water. Crude sodium chloride thus obtained contains CaSO4, CaCl2, MgCl2 as impurities and is deliquescent. Pure NaCl is obtained by passing HCl gas through saturated solution of crude NaCl. Due to common ion effect pure NaCl get precipitated.
Approximately 50 lakh tons of salt produced annually in India by solar evaporation.
Properties :
i) Sodium chloride melts at 1081K.
ii) It has a solubility of 36.09 in 100g of water at 237K.
iii) When heated with conc. H2SO4 and MnO2 it liberates chlorine gas.
Uses :
i) It is used as common salt or table salt for domestic purpose.
ii) It is used for the preparation of Na2O2, NaOH, Na2CO3, etc.
iii) Used as a preservative for meat, fish, etc.
iv) It is used in the salting process of soap and in the freezing mixtures to lower down temperature of ice.