What reaction is involved when esters are made?

Answer 1

Esterification is when an alcohol and a carboxylic acid react together (with sulphuric acid as a catalyst) to form an ester.

Example:

Butanol (alcohol) + pentanoic acid (carboxylic acid) --> butyl pentanoate (ester)

Source: Chemistry: The Study of Matter and Change by James E. Brady and John R. Holum

Answer 2

Dehydration is the reaction involved when esters are made. You start with a molecule with a hydroxyl group (-OH), like glucose. Esterification brings hydroxyl groups from each of two molecules together:

glu-OH HO-glu

The hydroxyl is removed from one molecule, and the hydrogen from the other:

glu-O- -glu H- -OH -------> glu-O-glu + H2O

And everything fits together: a new ester, and an extra water molecule. Since a water was removed in the process, this is a dehydration reaction.

Answer 3

Esterification is the chemical process for making esters which are compounds of another chemical structure. The process involved is heating a carboxylic acid with an alcohol which removes the water that is formed.

Answer 4

Acid-base-catalysed hydrolyses are very common; one example is the hydrolysis of amides or esters. Their hydrolysis occurs when the nucleophile (a nucleus-seeking agent, e.g., water or hydroxyl ion) attacks the carbon of the carbonyl group of the ester or amide. In an aqueous base, hydroxyl ions are better nucleophiles than polar molecules such as water. In acids, the carbonyl group becomes protonated, and this leads to a much easier nucleophilic attack. The products for both hydrolyses are compounds with carboxylic acidgroups.

Perhaps the oldest commercially practiced example of ester hydrolysis is saponification (formation of soap). It is the hydrolysis of atriglyceride (fat) with an aqueous base such as sodium hydroxide (NaOH). During the process, glycerol is formed, and the fatty acidsreact with the base, converting them to salts. These salts are called soaps, commonly used in households.

In addition, in living systems, most biochemical reactions (including ATP hydrolysis) take place during the catalysis of enzymes. The catalytic action of enzymes allows the hydrolysis of proteins, fats, oils, and carbohydrates. As an example, one may considerproteases (enzymes that aid digestion by causing hydrolysis of peptide bonds in proteins). They catalyse the hydrolysis of interior peptide bonds in peptide chains, as opposed to exopeptidases (another class of enzymes, that catalyse the hydrolysis of terminal peptide bonds, liberating one free amino acid at a time).

However, proteases do not catalyse the hydrolysis of all kinds of proteins. Their action is stereo-selective: Only proteins with a certain tertiary structure are targeted as some kind of orienting force is needed to place the amide group in the proper position for catalysis. The necessary contacts between an enzyme and its substrates (proteins) are created because the enzyme folds in such a way as to form a crevice into which the substrate fits; the crevice also contains the catalytic groups. Therefore, proteins that do not fit into the crevice will not undergo hydrolysis. This specificity preserves the integrity of other proteins such as hormones, and therefore the biological system continues to function normally.

Upon hydrolysis, an amide converts into a carboxylic acid and an amine or ammonia. The carboxylic acid has a hydroxyl group derived from a water molecule and the amine (or ammonia) gains the hydrogen ion. The hydrolysis of peptides gives amino acids.

Many polyamide polymers such as nylon 6,6 hydrolyse in the presence of strong acids. The process leads to depolymerization. For this reason nylon products fail by fracturing when exposed to small amounts of acidic water. Polyesters are also susceptible to similarpolymer degradation reactions. The problem is known as stress corrosion cracking.

Answer 5

Esters are typically produced through a condensation reaction between an alcohol and a carboxylic acid in the presence of an acid catalyst. During this reaction, a water molecule is eliminated, and the ester product is formed.

Answer 6

When Esters are commonly formed by reaction of an acid and an alcohol. Ethanoic acid reacts with absoloute ethanol to give an ester.

Answer 7

Esterification is a reaction of a caboxylic acid with an alcohol, in the presence of a dehydrating agent (e.g. sulfuric acid).