Hydrochloric Acid Formula

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What is Hydrochloric Acid Formula?

Many people have used Muriatic acid in their houses. Mainly used as a cleaning agent for tiles, toiletries, and marbles, it is the common name for Hydrochloric acid. Hydrochloric acid or Hydrogen chloride gas is an ionic compound formed by electrons’ transfer between Hydrogen and Chloride ions. In this bond, the negatively charged Chloride ion accepts the free electron from the positively charged Hydrogen ion to form the ionic bond between them. However, Hydrogen Chloride gas is a polar covalent compound. 

What is the Hydrochloric Acid Chemical Formula?

The molecular formula of Hydrochloric acid is HCl. It contains a Hydrogen atom bonded to a Chlorine atom. The type of bond formed between the two ions depends on the two ions’ electronegativity. Such a difference is also determined by the environment in which it is forming the bond. For example, the difference in electronegativity of the two ions in the gaseous stage is such that it creates a polar covalent bond. Therefore, Hydrogen chloride gas is covalent. However, in an aqueous solution like water, this difference in electronegativity of the two ions increases to such an extent that it starts forming an ionic bond.

The Structural Formula of Hydrochloric Acid

Hydrochloric acid is a simple compound consisting of two atoms. The bond angle is 180 degrees. It is sp3 hybridized.

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Fig. Structure of Hydrochloric acid.

What are the Properties of Hydrochloric Acid?

The maximum concentration of Hydrochloric acid is 38%. Industrial grade acid can have a maximum concentration of 35%. For commercial purposes, muriatic acid is mainly prepared at a concentration of 28-32%. The physical properties of Hydrochloric acid change with the concentration. For example, the density, viscosity, and vapour pressure of Hydrochloric acid increase with the concentration of the acid. Melting point, boiling point, and specific heat decrease with concentration. The pH of Hydrochloric acid is in the acidic range, ranging from -0.5 to -1.1, depending on the concentration of the acid. 

Hydrochloric acid is a strong acid as it readily releases Hydrogen ions in aqueous solutions. The dilute hydrochloric acid formula is H+-Cl-. It is a commonly used laboratory and commercial reagent since it reacts with several metals and compounds.

What are the Uses of Hydrochloric Acid?

  • It is a commonly used laboratory reagent.

  • It is used in the production of plastics, dyes, gelatin, and fertilizers.

  • It is used in the rubber, textile, and photography industries.

  • It is used in leather processing industries.

  • It is used for household cleaning.


Hydrochloric acid is a simple diatomic acid whose nature of bond depends on its environment. It is a polar covalent compound in gaseous form, while in an aqueous solution, it is ionic. The structure of the compound determines its physical and chemical properties. The acid is highly reactive and is used as a common laboratory and industrial reagent. It is also used for cleaning household items.

FAQ (Frequently Asked Questions)

1. Why is Hydrogen Chloride Gas Covalent, While Hydrochloric Acid Ionic?

Ans: The bond nature between the Hydrogen and chloride ion depends on the surrounding environment. Although the bond involves the sharing or transferring of one electron, the two ions share the electron to form a polar covalent bond in the gaseous form. That is why hydrogen chloride gas is polar covalent. However, in an aqueous solution, the difference in the two ions’ electronegativity increases so much that it forms an ionic bond. Therefore, hydrochloric acid is ionic in nature.

2. What is the Structure of Hydrochloric Acid?

Ans: Hydrochloric acid is a simple diatomic compound involving Hydrogen and Chlorine atoms. The bond angle is 180 degrees. It is sp3 hybridized.

3. What is the Chemical Name of Muriatic Acid?

Ans: Chemical name - Hydrochloric acid

The concentration of Muriatic acid ranges between 28% to 32% for household needs. However, the acid’s concentration can increase by up to 38%.