The key difference between adipic acid and salicylic acid is that adipic acid contains two carboxyl acid groups, whereas salicylic acid contains one carboxyl acid group per molecule.
Adipic acid and salicylic acid are organic compounds. They contain carboxylic groups as their functional group. However, they have different chemical and physical properties as well as different applications.
CONTENTS
1. Overview and Key Difference
2. What is Adipic Acid
3. What is Salicylic Acid
4. Side by Side Comparison – Adipic Acid vs Salicylic Acid in Tabular Form
5. Summary
What is Adipic Acid?
Adipic acid is an organic compound that is very important as a precursor for the production of nylon. The chemical formula for this molecule is (CH2)4(COOH)2. This is mostly a synthetic organic compound, but it can occur very rarely in nature. When produced industrially, it appears as white crystals, and it is odourless.
Figure 01: Structure of Adipic Acid
When considering the production of adipic acid, we can produce it from a mixture of cyclohexanone and cyclohexanol. The industrial term for this mixture is “KA oil”. It says that this mixture is a Ketone-Alcohol oil. Adipic acid forms from the oxidation of KA oil with nitric acid. However, there are some alternative methods for the production, such as oxidative cleavage of cyclohexene in the presence of hydrogen peroxide.
The most common use of adipic acid is as a precursor for the production of nylon polymer material. This is a polycondensation reaction which occurs in the presence of hexamethylene diamine. Also, adipic acid is important as a matrix compound for drugs in medication for the pH-independent release of the drug. Moreover, adipic acid is important as a food additive for flavour and as a gelling aid.
What is Salicylic Acid?
Salicylic acid is an organic compound, and it is useful as a medication that helps to remove the outer layer of the skin. It is a colourless to white crystalline solid that is odourless. The chemical formula of salicylic acid is C7H6O3. The molar mass of this compound is 138.12 g/mol. The melting point of salicylic acid crystals is 158.6 °C and, it decomposes at 200 °C. These crystals can undergo sublimation at 76 °C (sublimation is the conversion of a solid directly into its vapour phase without going through a liquid phase). The IUPAC name of salicylic acid is 2-Hydroxybenzoic acid.
Figure 02: Structure of Salicylic Acid
Salicylic acid is used as a medication. It is used to treat warts, dandruff, acne and other skin disorders due to its ability to remove the outer layer of the skin. Therefore, salicylic acid is a major ingredient used in manufacturing skin care products; for example, it is used in some shampoos to treat dandruff. Also, it is used in manufacturing Pepto-Bismol, a medication used to treat gastrointestinal disorders. Salicylic acid is also used as a food preservative.
What is the Difference Between Adipic Acid and Salicylic Acid?
Adipic acid is an organic compound that is very important as a precursor for the production of nylon. Salicylic acid is an organic compound, and it is useful as a medication that helps to remove the outer layer of the skin. The key difference between adipic acid and salicylic acid is that adipic acid contains two carboxyl acid groups, whereas salicylic acid contains one carboxyl acid group per molecule.
Below infographic tabulates the differences between adipic acid and salicylic acid.
Summary – Adipic Acid vs Salicylic Acid
Adipic acid and salicylic acid are organic compounds containing carboxylic acid groups. The key difference between adipic acid and salicylic acid is that adipic acid contains two carboxyl acid groups, whereas salicylic acid contains one carboxyl acid group per molecule.
Reference:
1. “Adipic Acid.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine, Available here.
2. Bellis, Mary. “The History of Aspirin.” ThoughtCo, Feb. 11, 2020, Available here.
Image Courtesy:
1. “Adipic acid structure” By User:Edgar181 – Own work; uploaded to en-wiki by User:Edgar181 as en:Image:Adipic acid structure.png; transferred to Commons by User:InfoCan (Public Domain) via Commons Wikimedia
2. “Salicylic acid chemical structure” (CC BY-SA 3.0) via Commons Wikimedia