Difference Between Acetic Acid and Glacial Acetic Acid

According to the IUPAC nomenclature, the Acetic acid (CH3COOH) is named Ethanoic Acid. In educational chemistry for students, it can be considered to be one of the simplest carboxylic acids that are existent. It is an organic chemical compound that possesses diacritic sour flavor and pungent odor, which is quite perceivable as the scent and flavor of Vinegar. Vinegar is a common household essential, and it contains 3-9% of acetic acid. The main difference between normal acetic acid and Glacial acetic acid lies in concentration. Glacial Acetic Acid has less amount of water concentration, which is 1%. 

What is Acetic Acid?

Acetic Acid comes in the list of simplest carboxylic acid after the Formic acid (HCOOH). In the earlier days, acetic acid was synthesized by the acetic fermentation of ethyl alcohol. Due to bacterial enzymes' reaction, the alcohol gets readily oxidized by the oxygen to finally acetic acid. The massive industrial process of synthesizing acetic acid is the direct catalytic oxidation of butane or acetaldehyde.    

It quickly dissolves in water due to the massive polarity of the O-H bond. The intramolecular hydrogen bonds of acids are greater than the alcohol bonds, which ensures the unobstructed solubility of acetic acid.  

As far as chemical properties are concerned, acetic acid partakes in chemical reactions with the disruption of the O-H bonds in the carboxyl group. Due to its higher water solubility, it demonstrates the typical chemical properties of the organic acids and gets dissociated according to this equation:

CH3COOH → CH3COO- + H+

Being a weak acid, the degree of electrolytic dissociation is very poor than those strong acids. Acetic acid significantly reacts with highly electropositive metals, salts of weak acids, basic oxides, and hydroxides in order to produce acetates. 

Acetic acid reacts with the alcohols in the presence of strong acids and thus it leads to the formation of ester. The entire process is known as “esterification”. Abreast of these chemical reactions, acetic acid possesses a density of 1.04 gm/cm3 and the melting point is 16.5-degree centigrade.  

The usage of Acetic Acid: 

There is myriad usage of acetic acid in food industries and households. 5-18% of the acetic acid solution is used for the fixation of photographic films, to treat a jellyfish sting, and to dispel calcium deposits from boilers and cranes. The robust usage of acetic acid as a preservative for silage as it averts the outgrowth of fungi and bacteria.

What is Glacial Acetic Acid?

As the name suggests “Glacial”, this pure, anhydrous liquid forms ice-like crystals at the temperature below 16.7-degree centigrade. This is the pure form of acetic acid and it is completely colorless liquid and hygroscopic in nature. The main difference between acetic acid and glacial acetic acid is water concentration. Due to the high concentration of glacial acetic acid, it contains only 1% of water and 99.5% of pure acetic acid. Due to the presence of a higher percentage of acid, it becomes highly corrosive.  

The Glacial Acetic acid possesses a high boiling temperature of 118-degree centigrade. If you are contemplating the reason, it is nothing but the formation of stable hydrogen bonds between two molecules of acetic acid in the dimer form. The density and flammability are 1.05 gm/ml and 39-degree centigrade. 

Due to its high corrosiveness, its vapors often cause irritation to the eyes and nose. If it comes into contact with eyes and skin, it will lead to the lesion. The Glacial acetic acid is an eminent polar-base solvent and so that it has been used in the production of the followings:

  • Propylene Terephthalate

  • Aniline

  • Terephthalic Acid

  • Synthetic Camphor

Glacial Acetic acid is pretty much effective while producing ester. Esterification is done along with the water in glacial acetic acid. If there is a presence of certain water into an acetic acid solution, the equilibrium will be highly affected by the synthesis reaction and the meager amount of ester will be obtained at the end. So, glacial acetic acid is far better than the normal acetic acid.            

Crystal Composition of Glacial Acetic Acid at 16.5-degree C

Difference between Acetic acid and Glacial Acetic Acid:

1. Definition:

  • Acetic Acid: It is an organic and colorless weak acid, with a pungent smell.

  • Glacial Acetic Acid: It is the concentrated and pure form of acetic acid.

2. Water Content:

  • Acetic Acid:It contains a significant amount of water and it is available in the diluted form.

  • Glacial Acetic Acid: Being a pure form of acetic acid, it contains 1% of water. It is concentrated in nature.

3. Usage:

  • Acetic Acid: It is non-toxic in nature and used as a food additive.  

  • Glacial Acetic Acid: It is highly corrosive in nature and injurious to the skin. 

4. Crystallization:

  • Acetic Acid: It does not form any crystals.

  • Glacial Acetic Acid: It forms crystals at temperatures below 16.5-degree centigrade. 

5. Occurrence in Nature:

  • Acetic Acid: In the environment, it is found in animal organisms and plants.

  • Glacial Acetic Acid: It is chemically manipulated and does not occur in nature. It has the pure and anhydrous form of acetic acid. 

6. Production:

  • Acetic Acid: It can be produced by direct catalytic oxidation of butane or acetaldehyde, or by acetic fermentation, or catalyzed by rhodium-iodine.  

  • Glacial Acetic Acid: It can be synthesized by dipping acetic acid solution over a ‘stalactite’ of sturdy glacial acetic acid. Thereafter, the pure acetic acid will set to the glacial acetic acid and all the contaminants will dispel with the liquid portion. 

FAQ (Frequently Asked Questions)

1. What is the Percentage of Acetic Acid in Vinegar?

A: Vinegar contains 3-9% of acetic acid.

2. Is Acetic Acid a Strong Acid?

A: Acetic acid is considered a weak acid as it does not dissolve very much in the solution.

3. How Does Glacial Acetic Acid Form?

A: It forms under 16.5-degree centigrade.

4. What is the Difference Between Acetic Acid and Glacial Acetic Acid?

A: The key difference between both acids is - acetic acid contains a significant amount of water and whereas glacial acetic acid contains less than 1% of water.

5. Why is Glacial Acetic Acid Corrosive in Nature?

A: It possesses 99.5% of pure acetic acid so that is highly concentrated. This is the reason behind its corrosiveness.