Question

In the presence of an acid catalyst, the major product of butanoic acid and 1 -pentanol is: (A) \(\quad 1\) -butoxy-1-pentanol. (B) \(\quad\) butyl pentanoate. (C) \(\quad 1\) -pentoxy-1-butanol (D) \(\quad\) pentyl butanoate

Short answer

The major product is pentyl butanoate (Option D).

Step-by-step solution

- Identify Reactants and Catalyst

The reactants are butanoic acid and 1-pentanol. The catalyst is an acid.

- Recognize Reaction Type

This reaction involves carboxylic acid and alcohol with an acid catalyst, indicating that esterification is likely to occur.

- Understand Esterification Mechanism

In an esterification reaction, the carboxylic acid (butanoic acid here) reacts with the alcohol (1-pentanol) to form an ester and water.

- Form the Ester

The OH group from the carboxylic acid and an H from the alcohol combine to form water, and the remaining parts of the molecules form the ester: butanoic acid (C4H8O2) loses OH, and 1-pentanol (C5H12O) loses H.

- Identify the Major Product

The major product is formed by combining butanoic acid and 1-pentanol into an ester. This product is pentyl butanoate (Option D).

Key concepts

Carboxylic Acid

Carboxylic acids are a vital class of organic compounds often found in various chemical reactions, including esterification. They possess the functional group -COOH, consisting of a carbonyl group (C=O) and a hydroxyl group (OH). This dual presence allows carboxylic acids to act as both acids (donating H+) and electrophiles in reactions. Butanoic acid, our subject, combines four carbon atoms, forming a molecular structure with the formula C4H8O2. This versatile nature of carboxylic acids makes them crucial in creating numerous organic compounds.

Alcohol

Alcohols are compounds that contain one or more hydroxyl groups (-OH) attached to a saturated carbon atom. In organic chemistry, alcohols play an essential role due to their reactivity. They can donate hydroxyl groups during esterification reactions, forming water as a byproduct. Specifically, 1-pentanol, which features five carbon atoms and follows the structure C5H12O, is our key alcohol component, reacting with butanoic acid to form an ester. The -OH group in alcohols is highly reactive, lending them to various chemical transformations.

Acid Catalyst

An acid catalyst is a substance that speeds up chemical reactions by donating protons (H+) but does not get consumed in the process. In esterification, a common reaction in organic chemistry, an acid catalyst like sulfuric acid is often used. This catalyst helps by protonating the carboxyl group of the carboxylic acid, making it a better electrophile. Consequently, ester formation becomes more efficient. The acid catalyst is crucial as it ensures the reaction proceeds at a reasonable rate without being used up.

Organic Chemistry Reactions

Organic chemistry reactions encompass transformations within organic compounds. Esterification is a classic example where a carboxylic acid reacts with an alcohol to produce an ester and water. Understanding the mechanism involves recognizing the reactants, intermediates, and products. Butanoic acid reacts with 1-pentanol under acidic conditions to yield pentyl butanoate, exemplifying a classic organic transformation. These reactions form the foundation of organic synthesis, crucial for creating various compounds in pharmaceuticals, materials science, and beyond.

MCAT Preparation

The MCAT exam tests knowledge in various scientific principles, including organic chemistry. Understanding esterification is essential for problems involving carboxylic acids or alcohols. Key points to remember include:

• Identifying functional groups like -COOH in carboxylic acids and -OH in alcohols.
• Recognizing the role of acid catalysts in facilitating reactions.
• Following reaction steps for mechanism clarity.

Practice problems on esterification can enhance preparedness, contributing to better MCAT scores and deeper comprehension of organic chemistry principles.