Acid anhydrides

Definition

Acid anhydrides are chemical compounds derived from acids by the removal of water. They typically react with water to form corresponding acids.

5 Must Know Facts For Your Next Test

1. Acid anhydrides are usually formed from carboxylic acids and can be represented by the general formula $(RCO)_2O$.
2. They react readily with water in a hydrolysis reaction to yield carboxylic acids.
3. Acid anhydrides can be used in organic synthesis to introduce acyl groups into other molecules.
4. The reactivity of acid anhydrides is higher than that of their corresponding acids due to their electrophilic nature.
5. Common examples include acetic anhydride and sulfur trioxide, which is the acid anhydride of sulfuric acid.

Review Questions

• What is the general formula for a carboxylic acid-derived acid anhydride?
• Describe the reaction that occurs when an acid anhydride comes into contact with water.
• Name two common examples of acid anhydrides.

Related terms

Carboxylic Acid:

Organic acids characterized by the presence of a carboxyl group $(COOH)$. They can be converted into acid anhydrides.

Hydrolysis:

A chemical reaction in which a compound reacts with water, often leading to the decomposition of that compound.

Electrophile: A molecule or ion that accepts a pair of electrons to form a new covalent bond. Acid anhydrides act as electrophiles in many reactions.