Hydrogen Chloride vs Hydrochloric Acid
We normally identify an acid as a proton donor. Acids have a sour taste. Lime juice, vinegar are two acids we come across at our homes. They react with bases producing water, and also they react with metals to form H2, thus increase metal corrosion rate. Acids can be categorized into two, based on their ability to dissociate and produce protons. Strong acids are completely ionized in a solution, to give protons. Weak acids are partially dissociates and give fewer amounts of protons. Ka is the acid dissociation constant. It gives an indication of the ability to lose a proton of a weak acid.
To check whether a substance is an acid or not we can use several indicators like litmus paper or pH paper. In the pH scale, acids are represented from 1-6. An acid with pH 1 is said to be very strong, and as the pH value increases, acidity is decreased. Moreover, acids turn blue litmus to red.
All the acids can be divided into two as organic acids and inorganic acids depending on their structure. Hydrochloric acid is a commonly used strong inorganic acid. It is also known as mineral acid, and it is derived from mineral sources. Inorganic acids release protons when dissolved in water.
Hydrogen chloride is in the gaseous form, and it has the molecular formula of HCl. It is a gas at the room temperature and colorless. This is a diatomic molecule, and the molar mass of it is 36.46 g mol−1. It has a pungent odor.
The chlorine atom and the hydrogen atom of the molecule are connected via a covalent bond. This bond is polar due to more electronegativity of chlorine compared to hydrogen. Hydrogen chloride is highly soluble in water. Following is the dissociation reaction of HCl in aqueous medium.
HCl +H2O → H3O+ +Cl–
Hydrogen chloride is produced from hydrogen gas and chlorine gas. The produced hydrogen chloride is mainly used to produce hydrochloric acid.
Hydrochloric acid, which is also denoted as HCl, is mineral acid, which is very strong and highly corrosive. This is a colorless, nonflammable liquid. It is stable, but readily reacts with bases and metals. It has the capability to ionize and donate only one proton. Since it is a strong acid, the acid dissociation constant of HCl is very large.
HCl is used in fertilizer, rubber, textile and dye manufacturing industries. Also, it is a widely used acid in laboratories for base titrations, or to provide acidic media, or to neutralize basic solutions, etc.
What is the difference between Hydrogen Chloride and Hydrochloric Acid?
- Both hydrogen chloride and hydrochloric acid are the same compound, but hydrogen chloride is in the gaseous phase whereas hydrochloric acid is a solution.
- When hydrogen chloride dissolves in water, hydrochloric acid forms.
- Hydrogen chloride is a colorless gas. When it is associated with humidity, it can form white fumes, which is hydrochloric acid.