What Happens When Carboxylic Acid Reacts with Ammonia?

When a carboxylic acid reacts with ammonia (NH₃), it forms an amide.

The Reaction: Carboxylic Acids and Ammonia

The reaction between a carboxylic acid and ammonia is a fundamental process in organic chemistry that results in the formation of an amide. An amide is a functional group derived from a carboxylic acid where the hydroxyl group (-OH) is replaced by an amine group (-NH₂, -NHR, or -NR₂).

According to the reference, the addition of ammonia (NH₃) to a carboxylic acid forms an amide.

However, it's important to note a practical aspect highlighted in the reference: the reaction is very slow in the laboratory at room temperature. This means that while the reaction can occur, it typically requires conditions beyond just mixing at standard room temperature for a reasonable reaction rate.

The Mechanism: Forming the Amide Bond

The core of this reaction involves the formation of a new chemical bond. A bond is formed between the nitrogen atom from the ammonia molecule and the carbonyl carbon atom of the carboxylic acid.

During this process, water molecules are split out. This is characteristic of a condensation reaction, where two molecules combine, and a small molecule like water is eliminated.

The general reaction can be visualized conceptually as:

Carboxylic Acid (-COOH) + Ammonia (NH₃) → Amide (-CONH₂) + Water (H₂O)

This forms a primary amide where the nitrogen is bonded directly to the carbonyl carbon and two hydrogen atoms.

Practical Considerations

As mentioned, the reaction's sluggishness at room temperature is a key practical point. This often necessitates heating the reaction mixture to drive the reaction to completion at a faster rate. However, based only on the provided reference, we know it's specifically very slow in the laboratory at room temperature.

Summary of Key Changes

Here's a simple overview of what happens during the reaction:

This reaction is crucial for synthesizing amides, which are found in many important compounds, including proteins (where amide bonds, also called peptide bonds, link amino acids) and synthetic polymers like nylon.