2.4.3. Chemicals from Common Salt

By now you have learnt that the salt formed by the combination of hydrochloric acid and sodium hydroxide solution is called sodium chloride. This is the salt that you use in food. You must have observed in the above Activity that it is a neutral salt.

Sodium chloride is the chemical name for table salt. It is created when hydrochloric acid (HCl) reacts with sodium hydroxide (NaOH). This reaction produces sodium chloride (NaCl) and water (H2O). Sodium chloride is classified as a neutral salt, which means it does not affect the acidity or basicity of a solution when dissolved in water.

Think of sodium chloride like the common salt you add to your food. Just like salt enhances the flavor of food, sodium chloride is a key player in our body and in chemical reactions, providing essential ions that help with hydration and cell function.

Seawater contains many salts dissolved in it. Sodium chloride is separated from these salts. Deposits of solid salt are also found in several parts of the world. These large crystals are often brown due to impurities. This is called rock salt. Beds of rock salt were formed when seas of bygone ages dried up. Rock salt is mined like coal.

Sodium chloride can be obtained from seawater, which contains various dissolved salts. Through evaporation or crystallization processes, we can isolate sodium chloride from other salts. Additionally, large underground deposits of sodium chloride, known as rock salt, exist, which were formed from ancient seas that dried up over time. Rock salt is extracted through mining processes similar to coal mining.

Imagine walking along a beach and picking up a handful of salt. That’s similar to how chefs might harvest salt from the sea! Rock salt is like finding leftover treasures from ancient times, buried underground from seas that existed millions of years ago.

You must have heard about Mahatma Gandhi’s Dandi March. Did you know that sodium chloride was such an important symbol in our struggle for freedom?

The Dandi March was a significant event in India’s struggle for independence. Mahatma Gandhi led this march to protest against the British salt tax, which made common salt a powerful symbol of oppression and resistance. By making salt from seawater, Gandhi aimed to show that Indians could produce their own salt instead of buying it from the British, highlighting self-reliance and defiance.

Think of sodium chloride not just as a seasoning, but as a historical artifact. Just like how we might cherish a piece of clothing or a memento that reminds us of an important event, sodium chloride from the Dandi March represents courage and the fight for independence, much like a powerful protest symbol.

The common salt thus obtained is an important raw material for various materials of daily use, such as sodium hydroxide, baking soda, washing soda, bleaching powder and many more. Let us see how one substance is used for making all these different substances.

Common salt is not only used for cooking but is also a key ingredient in the production of various chemicals. For example, when electricity is passed through a solution of sodium chloride (brine), it produces sodium hydroxide (NaOH), chlorine gas, and hydrogen gas. These products are useful in numerous applications ranging from cleaning agents to food preservation.

Think of common salt like a versatile tool in a toolbox. Just as one tool can be used to fix various things, common salt is used as a building block to create many everyday products, like baking soda for baking bread or sodium hydroxide for cleaning soda.

--