Salts

A salt is a combination of an anion of an acid and a cation of a base.

Examples – KCl, NaNO₃,CaSO₄, etc.

Salts are usually prepared by the neutralisation reaction of an acid and a base.

Common salt

Sodium Chloride (NaCl) is referred to as common salt because it’s used all over the world for cooking.

Family of salts

Salts having the same cation or anion belong to the same family. For example, NaCl, KCl, LiCl.

pH of salts

A salt of a strong acid and a strong base will be neutral in nature. pH = 7 (approx.).
A salt of a weak acid and a strong base will be basic in nature. pH > 7.
A salt of a strong acid and a weak base will be acidic in nature. pH < 7.
The pH of a salt of a weak acid and a weak base is determined by conducting a pH test.

Chemicals from common salt

Sodium chloride is a common salt. NaCl is its molecular formula. The fundamental element in our meals is sodium chloride. It is used in our food as a flavour enhancer as well as a preservative. From common salt, we may make the following four compounds.

Sodium hydroxide or lye or caustic soda
Baking soda or sodium hydrogen carbonate or sodium bicarbonate
Washing soda or sodium carbonate decahydrate
Bleaching powder or calcium hypochlorite

Preparation of Sodium hydroxide

The strong base sodium hydroxide is a common and useful one. Preparing a solution of sodium hydroxide (NaOH) in water requires extra caution because the exothermic reaction releases a lot of heat. It’s possible that the solution will spatter or boil. Here’s how to manufacture a sodium hydroxide solution safely, as well as recipes for a variety of NaOH strengths.

Chemical formula – NaOH
Also known as – caustic soda

Preparation (Chlor-alkali process):
Electrolysis of brine (solution of common salt, NaCl) is carried out.
At anode: Cl₂ is released
At cathode: H₂ is released
Sodium hydroxide remains in the solution.