Question

a. Write an equation for the acid hydrolysis of glyceryl trioleate (triolein). b. Write an equation for the NaOH saponification of glyceryl trioleate (triolein).

Short answer

a. Glyceryl trioleate + 3H2O → glycerol + 3 oleic acid. b. Glyceryl trioleate + 3NaOH → glycerol + 3 sodium oleate.

Step-by-step solution

Understanding Acid Hydrolysis

In acid hydrolysis, water and an acid (commonly HCl or H2SO4) are used to break down an ester like glyceryl trioleate into glycerol and fatty acids. Triolein, specifically, will be broken down into glycerol and three molecules of oleic acid.

Write the Chemical Structure

Glyceryl trioleate (triolein) is a triglyceride composed of glycerol esterified with three oleic acid molecules. Its structure can be represented as: CH2-O-CO-(CH2)7-CH=CH-(CH2)7-CH3 | CH-O-CO-(CH2)7-CH=CH-(CH2)7-CH3 | CH2-O-CO-(CH2)7-CH=CH-(CH2)7-CH3

Equation for Acid Hydrolysis

When glyceryl trioleate undergoes hydrolysis in the presence of water and an acid catalyst, the reaction is: CH2-O-CO-(CH2)7-CH=CH-(CH2)7-CH3 | CH-O-CO-(CH2)7-CH=CH-(CH2)7-CH3 + 3H2O → CH2OH | CH2-O-CO-(CH2)7-CH=CH-(CH2)7-CH3 + 3 HOOC-(CH2)7-CH=CH-(CH2)7-CH3 | CHOH .

Understanding Saponification

Saponification is the base-catalyzed hydrolysis of triglycerides using NaOH (sodium hydroxide). This reaction will yield glycerol and the sodium salt of the fatty acid (soap).

Write the Chemical Structure for Saponification

For the saponification of glyceryl trioleate: CH2-O-CO-(CH2)7-CH=CH-(CH2)7-CH3 | CH-O-CO-(CH2)7-CH=CH-(CH2)7-CH3+ 3NaOH → CHOH | CH2-O-CO-(CH2)7-CH=CH-(CH2)7-CH3 +3 CH3(CH2)7CH=CH(CH2)7COONa | CHOH

Equation for Saponification

The overall chemical equation for the saponification process: CH2-O-CO-(CH2)7-CH=CH-(CH2)7-CH3 | CH-O-CO-(CH2)7-CH=CH-(CH2)7-CH3 + 3NaOH → CH2OH | CHOH + 3 CH3(CH2)7CH=CH-(CH2)7COONa

Key concepts

acid hydrolysis

Acid hydrolysis is a chemical reaction where water and an acid (like HCl or H2SO4) break down an ester into its components.
In the case of glyceryl trioleate (also known as triolein), the process separates the molecule into glycerol and fatty acids.
Specifically, triolein breaks down into one glycerol molecule and three molecules of oleic acid.
This happens because the acid helps to cleave the ester bonds in the triglyceride.
Here’s the chemical equation for the acid hydrolysis of glyceryl trioleate:
[CH2-O-CO-(CH2)7-CH=CH-(CH2)7-CH3|CH-O-CO-(CH2)7-CH=CH-(CH2)7-CH3|CH2-O-CO-(CH2)7-CH=CH-(CH2)7-CH3] + 3H2O →
[CH2OH|CHOH|CH2OH] + 3 [HOOC-(CH2)7-CH=CH-(CH2)7-CH3].
This shows how glyceryl trioleate is broken down into glycerol and oleic acids with the help of water and acid.

saponification

Saponification is the process of breaking down a triglyceride with a base, such as NaOH (sodium hydroxide).
It transforms the triglyceride into glycerol and the sodium salt of the fatty acids, commonly known as soap.
When glyceryl trioleate undergoes saponification, it produces glycerol and three molecules of sodium oleate.
The base (sodium hydroxide) helps to break the ester bonds in the triglyceride.
The chemical equation for the saponification of glyceryl trioleate is:
[CH2-O-CO-(CH2)7-CH=CH-(CH2)7-CH3|CH-O-CO-(CH2)7-CH=CH-(CH2)7-CH3|CH2-O-CO-(CH2)7-CH=CH-(CH2)7-CH3] + 3NaOH →
[CH2OH|CHOH|CH2OH] + 3 [CH3(CH2)7CH=CH-(CH2)7COONa].
This reaction results in glycerol and sodium oleate (a type of soap).

triglycerides

Triglycerides are fats and oils formed by three fatty acid molecules esterified to a glycerol molecule.
They serve as energy storage molecules in both plants and animals.
In their structure, each of the three hydroxyl (OH) groups on the glycerol reacts with the carboxyl (COOH) groups of fatty acids.
The bond that forms between the glycerol and fatty acids is called an ester bond.
Triglycerides can be broken down into their components through hydrolysis reactions, like acid hydrolysis or saponification.
These reactions separate the ester bonds, freeing glycerol and the fatty acids.

fatty acids

Fatty acids are long chains of hydrocarbons with a carboxyl group at one end.
They can be saturated or unsaturated based on the type of bond between the carbon atoms.
Saturated fatty acids have no double bonds, while unsaturated fatty acids have one or more double bonds.
In glyceryl trioleate, the fatty acid is oleic acid which is unsaturated due to the presence of a double bond.
The properties of fats and oils, including their melting points and reactivity, are influenced by the type of fatty acids they contain.
Fatty acids play crucial roles in metabolism and are also vital components of cell membranes.

glycerol

Glycerol, also known as glycerin, is a simple polyol compound.
It contains three hydroxyl (OH) groups that make it highly soluble in water and capable of forming hydrogen bonds.
In the context of triglycerides, glycerol forms the backbone to which fatty acids are esterified.
Upon hydrolysis (both acid and base hydrolysis), glycerol is released along with fatty acids.
Glycerol has a variety of applications in food, pharmaceuticals, and cosmetics due to its moisturizing and sweetening properties.