Salt is the ionic product of an acid‐base reaction. In everyday language, the word salt implies sodium chloride, NaCl, table salt. In the language of chemistry, however, salt is a general term meaning any ionic compound formed from the reaction between an acid and a base. Hydrogen chloride and sodium hydroxide, for example, react to produce the salt sodium chloride and water:
Seawater is salty and we obtain this salt, by evaporating sea water in salt pans. The salt obtained from seawater is not pure sodium chloride (NaCl), but contains many other salts in smaller proportion. These are KCl, KI, MgI2, MgCl2 etc. These are salts of other metals like potassium and magnesium. They are formed when alkalis like KOH and Mg(OH)2 react with acids like HCl or HI etc. Metal atoms donate electrons and form positive ions. So, they can replace hydrogen ion from an acid and make the respective salt. The OH− of the base combines with H+ of an acid and forms water.