Question

Distinguish between esterification and saponification reactions of organic compound.

Answer 1

Step 1

Esters are organic compound that contains a functional group $-\mathrm{COO}-$.

The long-chain carboxylic acids that contain sodium and potassium salts are called soaps.

Step 2

Esterification is a reaction in which organic acid reacts with alcohol in the presence of acid catalyst conc. Sulphuric acid (${\mathrm{H}}_2{\mathrm{SO}}_4$) to form an ester product.

Heat energy is needed for esterification.

Examples:

The reaction of Acetic acid (${\mathrm{CH}}_3\mathrm{COOH}$) with Ethanol (${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$) in the presence of conc. ${\mathrm{H}}_2{\mathrm{SO}}_4$ forms an Ethyl acetate (${\mathrm{CH}}_3{\mathrm{COOC}}_2{\mathrm{H}}_5$) and water as products.

1. The chemical equation of esterification reaction is written as:

$$\begin{gathered} {\mathrm{CH}}_3\mathrm{COOH}+{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}\stackrel{\mathrm{conc}.{\mathrm{H}}_2{\mathrm{SO}}_4}{\to }{\mathrm{CH}}_3{\mathrm{COOCH}}_3+{\mathrm{H}}_2\mathrm{O} \\ (\mathrm{acetic}\mathrm{acid})\left(\mathrm{ethanol}\right)(\mathrm{ethyl}\mathrm{acetate})\mathrm{water} \end{gathered}$$

2. The reaction of benzoic acid ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{COOH}$ with methanol ${\mathrm{CH}}_3\mathrm{OH}$ in an acidic medium gives phenyl acetate ${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{COOCH}}_3$.

$$\begin{gathered} {\mathrm{C}}_6{\mathrm{H}}_5\mathrm{COOOH}+{\mathrm{CH}}_3\mathrm{OH}\stackrel{{\mathrm{H}}_2{\mathrm{SO}}_4}{\to }{\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{COOCH}}_3+{\mathrm{H}}_2\mathrm{O} \\ (\mathrm{Benzoic}\mathrm{acid})\left(\mathrm{Methanol}\right)(\mathrm{Phenyl}\mathrm{acetate})\left(\mathrm{Water}\right) \end{gathered}$$

Esters are used to making perfumes.

Step 3

Saponification is a reaction in which oil or fat is converted into alcohol and soap by the action of a strongly alkaline medium.

Heat energy does not require for saponification reaction.

Examples:

1. The reaction of ethyl acetate ${\mathrm{CH}}_3{\mathrm{COOCH}}_2{\mathrm{CH}}_3$ with a strong alkali base in the basic medium gives the ethyl alcohol ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$ and sodium acetate ${\mathrm{CH}}_3\mathrm{COONa}$ product.

$$\begin{gathered} {\mathrm{CH}}_3{\mathrm{COOCH}}_2{\mathrm{CH}}_3\stackrel{\mathrm{NaOH}}{\to }{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}+{\mathrm{CH}}_3\mathrm{COONa} \\ (\mathrm{Ethyl}\mathrm{acetate})\left(\mathrm{Ethanol}\right)(\mathrm{Sodium}\mathrm{acetate}) \end{gathered}$$

2. The reaction of triglyceride with Sodium hydroxide ($\mathrm{NaOH}$) in the presence of a basic medium forms the Glycerol and Sodium palmitate product.

The chemical equation of saponification reaction is written as:

$$\begin{gathered} ({\mathrm{CH}}_3-{{\left({\mathrm{CH}}_2\right)}_{14}-{\mathrm{COOCH}}_2)}_2-({\mathrm{CH}}_3-{\left({\mathrm{CH}}_2\right)}_{14}-\mathrm{COO}-\mathrm{CH})+3\mathrm{NaOH}\to {\mathrm{CH}}_2\mathrm{OH}-\mathrm{CHOH}-{\mathrm{CH}}_2\mathrm{OH}+{\mathrm{CH}}_3-{\left({\mathrm{CH}}_2\right)}_{14}-\mathrm{COONa}(\mathrm{Sodium}\left(\mathrm{Glycerol}\right)(\mathrm{Sodium}\mathrm{palmitate}) \\ \left(\mathrm{Triglyceride}\right)(\mathrm{Sodium}\mathrm{hydroxide})\left(\mathrm{Glycerol}\right)(\mathrm{Sodium}\mathrm{palmitate}) \end{gathered}$$

Saponification reaction is useful in soap production.