Butyric Acid

Definition

Butyric acid is a short-chain fatty acid with the chemical formula CH3CH2CH2COOH. It is a colorless, oily liquid with a distinctive unpleasant odor, and is found naturally in butter, parmesan cheese, and the digestive tract of humans and animals.

5 Must Know Facts For Your Next Test

1. Butyric acid is the simplest member of the saturated straight-chain fatty acids, with four carbon atoms.
2. It is produced by the fermentation of carbohydrates and plays a role in the production of energy in the body.
3. Butyric acid is used in the production of various chemicals, including esters, which are used as solvents and flavoring agents.
4. The characteristic odor of butyric acid is often associated with rancid butter or parmesan cheese.
5. Butyric acid has been studied for its potential health benefits, including its anti-inflammatory and anti-cancer properties.

Review Questions

• Explain how the structure of butyric acid relates to its naming and classification as a carboxylic acid.
  • Butyric acid is a carboxylic acid because it contains a carboxyl group (-COOH) at the end of its four-carbon aliphatic chain. The name 'butyric' comes from the Latin word 'butyrum,' meaning butter, as butyric acid is a major component of butter. As a saturated, straight-chain fatty acid with four carbon atoms, butyric acid is classified as a simple, aliphatic carboxylic acid.
• Describe how the spectroscopic properties of butyric acid, such as its infrared (IR) and nuclear magnetic resonance (NMR) spectra, can be used to identify and characterize the compound.
  • The IR spectrum of butyric acid would show a characteristic absorption band around $\SI{1700}{cm^{-1}}$ due to the carbonyl (C=O) stretch of the carboxyl group. Additionally, the O-H stretch of the hydroxyl group would appear around $\SI{2500-3300}{cm^{-1}}$. In the $^{1}$H NMR spectrum, the methylene (CH$_2$) protons would appear as multiplets, while the methyl (CH$_3$) protons would show a triplet. The carboxylic acid proton would be observed as a broad singlet around $\SI{11}{ppm}$. These spectroscopic features can be used to confirm the presence and structure of butyric acid in a sample.
• Evaluate the potential applications and significance of butyric acid in the context of carboxylic acids and nitriles, particularly in terms of its chemical reactivity, biological relevance, and industrial uses.
  • Butyric acid, as a carboxylic acid, can undergo various chemical reactions, such as esterification, amidation, and reduction, which make it a versatile building block for the synthesis of other organic compounds. In the biological context, butyric acid is produced by the fermentation of dietary fiber in the human gut and has been studied for its potential health benefits, including its anti-inflammatory and anti-cancer properties. Industrially, butyric acid and its derivatives are used as solvents, plasticizers, and flavor additives in the food and cosmetic industries. The unique properties and diverse applications of butyric acid highlight its significance within the broader class of carboxylic acids and nitriles.

Related terms

Carboxylic Acid:

Carboxylic acids are organic compounds that contain a carboxyl group (-COOH), which consists of a carbonyl group (C=O) and a hydroxyl group (-OH).

Nitrile:

Nitriles are organic compounds that contain a cyano group (-C≡N), which consists of a carbon atom triple-bonded to a nitrogen atom.

Fatty Acid: Fatty acids are carboxylic acids with a long aliphatic chain, which can be either saturated or unsaturated.