What is the chemical formula of common salt?

Salt is an ionic compound that has formed by the neutralization reaction of an acid and a base. Sodium chloride is known as common salt because it is the most common and widely used salt in the world. It is a naturally occurring mineral that is found in seawater and many mineral deposits on land.

NaOH is a base as it contains OH^- ions. Hence, it cannot be classified as salt.

NaHCO₃ is an acidic salt, as on hydrolysis it produces NaOH, which is a strong base, and H₂CO₃ which is a weak acid.

NH₄Cl is also an acidic salt, as on hydrolysis it produces NH₄OH which is a weak base, and HCl which is a strong acid.