Write the formula of the triester formed from glycerol and stearic acid (Table 17.1).

Verified step by step guidance

1. Identify the structure of glycerol, which is a triol with the formula ${\text{C}}_3{\text{H}}_8{\text{O}}_3$. It has three hydroxyl ($-\text{OH}$) groups.
2. Identify the structure of stearic acid, which is a saturated fatty acid with the formula ${\text{C}}_{17}{\text{H}}_{35}\text{COOH}$.
3. Understand that a triester is formed when each hydroxyl group of glycerol reacts with the carboxyl group of a fatty acid, in this case, stearic acid, through an esterification reaction.
4. Write the general reaction for the formation of a triester: ${\text{C}}_3{\text{H}}_8{\text{O}}_3+3\times {\text{C}}_{17}{\text{H}}_{35}\text{COOH}\to \text{Triester}+3\times {\text{H}}_2\text{O}$.
5. Combine the structures to form the triester, which will have the formula ${\text{C}}_3{\text{H}}_5(\text{OOC}{\text{C}}_{17}{\text{H}}_{35}{)}_3$, representing the glycerol backbone with three stearate groups attached.

Key Concepts

Glycerol

Glycerol, also known as glycerin, is a simple polyol compound that serves as a backbone for triglycerides and phospholipids. It consists of three carbon atoms, each bonded to a hydroxyl group (-OH). In the context of esterification, glycerol reacts with fatty acids to form esters, specifically triglycerides when combined with three fatty acid molecules.

Stearic Acid

Stearic acid is a saturated fatty acid with an 18-carbon chain, commonly found in animal and plant fats. Its chemical formula is C18H36O2, and it is known for its role in forming triglycerides and phospholipids. When stearic acid reacts with glycerol, it forms a triester, contributing to the structure of fats and oils.

Esterification

Esterification is a chemical reaction between an alcohol and a carboxylic acid, resulting in the formation of an ester and water. In the case of glycerol and stearic acid, the reaction involves the hydroxyl groups of glycerol reacting with the carboxyl group of stearic acid. This process is crucial in the formation of triglycerides, which are important energy storage molecules in living organisms.