Problem 54 - Chemistry The Central Science

Question

Acetic anhydride is formed from two acetic acid molecules, in a condensation reaction that involves the removal of a molecule of water. Write the chemical equation for this process, and show the structure of acetic anhydride.

Step-by-Step Solution

Answer

The chemical equation for the condensation reaction between two acetic acid molecules (CH3COOH) forming acetic anhydride ((CH3CO)2O) and water (H2O) is: 2 CH3COOH -> (CH3CO)2O + H2O The structure of acetic anhydride is: O O || || CH3-C-O-C-CH3

Step 1: 1. Identify the structure of acetic acid

Acetic acid (CH3COOH) has the following structure: O || CH3-C-OH The carboxyl group (-COOH) is the functional group in acetic acid where the condensation reaction takes place.

Step 2: 2. Understand the condensation reaction

A condensation reaction is a reaction in which two molecules combine to form a larger molecule, with the elimination of a small molecule in the process, such as water or methanol. In this case, we have two acetic acid molecules reacting with one another to form acetic anhydride and a water molecule.

Step 3: 3. Write the chemical equation of the reaction

The chemical equation of the condensation reaction between two acetic acid molecules (CH3COOH) leading to the formation of acetic anhydride (CH3CO)2O and water (H2O) is: 2 CH3COOH -> (CH3CO)2O + H2O

Step 4: 4. Show the structure of acetic anhydride

During the condensation reaction, one hydrogen atom from the hydroxyl (-OH) group of one acetic acid molecule combines with the hydroxyl group (-OH) of the other acetic acid molecule to form water (H2O), leaving behind an acetic anhydride molecule. The structure of acetic anhydride is: O O || || CH3-C-O-C-CH3 In conclusion, the chemical equation for the formation of acetic anhydride from acetic acid molecules is: 2 CH3COOH -> (CH3CO)2O + H2O