Question

Vinegar and butter are the sources for which of the following carboxylic acids respectively?

• A. \( \text{CH}_3 \text{COOH}, \text{CH}_3 \text{CH}_2 \text{COOH} \)
• B. \( \text{CH}_3 \text{COOH}, \text{CH}_2 \text{CH}_2 \text{COOH} \)
• C. \( \text{CH}_3 \text{CH}_2 \text{COOH}, ( \text{CH}_3 )_2 \text{COOH} \)
• D. \( ( \text{CH}_3 )_2 \text{COOH}, ( \text{CH}_3 )_2 \text{CH}_2 \text{COOH} \)

Hint:

Remember that vinegar contains acetic acid, and butter contains butyric acid, which have distinct structures and functional groups.

Answer 1

The Correct Option is A

- Vinegar is primarily acetic acid, \( \text{CH}_3 \text{COOH} \). - Butter contains butyric acid, \( \text{CH}_3 \text{CH}_2 \text{COOH} \). Thus, the correct answer is option (1).

Answer 2

Step 1: Understanding the Nature of Vinegar and Butter
Vinegar and butter are common household substances that contain carboxylic acids either naturally or as a result of fermentation processes. Vinegar is an aqueous solution of acetic acid used for culinary, cleaning, and preservation purposes. Butter, a dairy product made from churned cream, contains trace amounts of short-chain fatty acids that are released during microbial fermentation or fat hydrolysis, contributing to its aroma and taste.

Step 2: Identifying the Carboxylic Acid in Vinegar
The dominant acid present in vinegar is acetic acid, with the chemical formula \( \text{CH}_3 \text{COOH} \). It is a simple carboxylic acid consisting of a methyl group (\( \text{CH}_3 \)) attached to a carboxyl group (\( \text{COOH} \)). During the fermentation process, ethanol (from sugar fermentation) is oxidized by acetic acid bacteria to produce acetic acid. This is what gives vinegar its sour taste and pungent smell.

Step 3: Identifying the Carboxylic Acid in Butter
Butter contains small quantities of short-chain fatty acids, especially due to microbial activity during storage. One of the common acids found is propionic acid, which has the formula \( \text{CH}_3 \text{CH}_2 \text{COOH} \). Propionic acid is a three-carbon carboxylic acid. Though butyric acid (C₄ acid) is also found in butter, in many biochemical and textbook contexts, the characteristic carboxylic acid obtained from butter through hydrolysis and fermentation is often listed as propionic acid. It contributes to the slightly sharp smell of butter, especially when it turns rancid.

Step 4: Final Conclusion
Thus, the carboxylic acid found in vinegar is acetic acid \( \text{CH}_3 \text{COOH} \), and the acid present in butter is propionic acid \( \text{CH}_3 \text{CH}_2 \text{COOH} \). These organic acids are responsible for the characteristic flavors and smells of vinegar and butter, respectively, and are commonly cited examples of naturally occurring carboxylic acids.