Hydrolysis

Hydrolysis is a chemical reaction that lead to the breaking of a complex compound into a simple molecule on reaction with water. The word Hydrolysis is composed of “hydro” and “lysis” which means water and breaking down. Hence, the meaning of hydrolysis is the breaking of a compound with the help of water via a chemical reaction. In these reactions, water is the key reagent that cleaves the bond and thus breaks the compound. Several examples of hydrolysis are hydrolysis of glucose, hydrolysis of ester and ether etc.

In this article, we will learn in detail about hydrolysis, its formula, types, and examples. We will also learn the comparison between Hydrolysis, hydration, and dehydration.

Hydrolysis

Table of Content

  • What is Hydrolysis?
  • Hydrolysis Reaction
  • Types of Hydrolysis
  • Example of Hydrolysis
  • Hydrolysis vs Dehydration
  • Applications of Hydrolysis

What is Hydrolysis?

Hydrolysis is a chemical reaction in which a compound reacts with water which ultimately leads breakage of bonds within that compound. This reaction creates two or more compounds which are simple ions. In hydrolysis, water splits into hydrogen ions (H⁺) and hydroxide ions (OH⁻) which then participate in the breaking of bonds within the compound itself.

The general formula for hydrolysis can be represented as

AB + H2O → AH + BOH

Where AB is the compound producing hydrolysis and AH and BOH are the compounds formed after the reaction.

Hydrolysis Reaction

Hydrolysis is a chemical process by which a chemical compound interacts with water molecules, which causes the splitting of bonds between atoms within the molecule and new bond formation. This reaction partially affects the scission of a molecule during the addition of a water molecule.

Here’s a generalized equation for a hydrolysis reaction:

Compound + Water → Product 1 + Product 2

In this environment, water is regarded as a reagent; it can be added to the molecule in several ways, or the product can depend on the compound structure and reaction conditions.

Hydrolysis Mechanism

Water decomposition is a process employed by water molecules to break bonds between a compound’s atoms. Here’s a brief overview:

  • Nucleophilic Attack: As a nucleophile, a water molecule forms a bond with a carbon located on the target compound’s electrophilic center.
  • Bond Cleavage: The atom under the coordination attack and the adjacent atom shares a bond that is harmful to the former.
  • Ionization: The initially created pieces can therefore either become ions or donate/withdraw protons, so as to form new species that will be more stable as the reaction intermediate is formed.
  • Formation of Products: When there is an electrophilic attack, there is a cleavage of the bonds, hence creating new compounds by one part exhibiting hydroxyl group (-OH) and the other the hydrogen ion (H⁺).

Fundamentally, hydrolysis reactions are the reaction between water molecules to transform complex chemical compounds into simpler products through the breakdown of the molecules.

Degree of hydrolysis

Hydrolysis involves the concept of degree of hydrolysis (α) that defines the amount of the compound hydrolytically deconstructed. It shows the efficiency of the hydrolysis reaction and the result is usually directly proportional to the fraction/percentage of the hydrolysis.

Mathematically, the degree of hydrolysis (α) can be calculated as the ratio of the number of moles of the compound that have undergone hydrolysis to the total number of moles of the compound initially present:

α = total moles of compound initially / moles of hydrolyzed compound

In some instance, the degree of hydrolysis may be expressed in percentage as well by multiplying the ratio result with 100 (it gives 100%).

Types of Hydrolysis

Hydrolysis reactions are classified into types determined by the catalyst and the substances undergoing hydrolysis. The main types of hydrolysis include:

  • Acid Hydrolysis
  • Base Hydrolysis
  • Enzymatic Hydrolysis
  • Salt Hydrolysis

Acid Hydrolysis

In Acid Hydrolysis, chemical bonds of the compound are broken in the presence of an acidic catalyst which gives hydrogen ions, H. Being in acidic conditions the specific bonds cleavages takes place. Acid hydrolysis is a phenomenon that very often occurs in biological systems e.g. digestion of food in the stomach using hydrochloric acid which assists in breaking down proteins into amino acids.

Base Hydrolysis

Basic hydrolysis involves the use of primary hydroxide ion (OH⁻). Hydroxide ions from a base to react with a compound resulting into cleavage of bonds. Like acid hydrolysis base hydrolysis yields simpler compounds or ions. Saponification, is one of the most known examples of base hydrolysis. This is a reaction between fat and oil and a strong base—for example sodium hydroxide—which produces soap and glycerol.

Enzymatic Hydrolysis

Enzymatic hydrolysis is the process of using biological catalysts which are enzymes to promote hydrolysis of specific bonds in organic molecules. Enzymes are highly specific and usually the most efficient catalysts in hydrolysis reactions without being being depleted. Several enzymes catalyze hydrolysis reactions in the living organism including the digestive enzymes such as amylase, that breaks down starch into glucose molecules during digestion.

Salt Hydrolysis

Salt hydrolysis is the process of the reaction between water and the ions of a salt which gives a resulting solution that is either acidic or basic. This type of hydrolysis happens when either the cation or the anion of the salt goes through hydrolysis to produce hydrogen ions (H+) or hydroxide ions (OH). The pH of the obtained solution is dependent on the strength relation of the acid and the base formed through hydrolysis.

Example of Hydrolysis

Hydrolysis is a chemical reaction in which a compound reacts with water and split into two products. The common examples of hydrolysis are mentioned below:

Hydrolysis of Ester

Ester hydrolysis requires a series of reactions in which a water molecule breaks the ester bond, producing a carboxylic acid and an alcohol as the products. For example, the hydrolysis of ethyl acetate: For example, the hydrolysis of ethyl acetate:

CH3COOCH2H5 + H2O →CH3COOH + C2H5

In this reaction, ethyl acetate reacts with water to form acetic acid and ethanol.

Sucrose Hydrolysis

Hydrolysis of sucrose involves in the breaking of the glycosidic bond present in sucrose which s done by the water molecules to give glucose and fructose. The catalyst acts on this reaction is the enzyme sucrase.

C12H22O11 + H2O → C6H12O6 + C6H12O6

In this reaction, sucrose reacts with water to form glucose and fructose.

Amide Hydrolysis

Amide hydrolysis involves a water molecule as a reactant and which is responsible for the breaking of an amide bond by water, resulting in the formation of a carboxylic acids and an amines. For example, the hydrolysis of acetamide:

CH3CONH2 + H2O + CH3COOH +NH3

In this reaction, acetamide reacts with water to form acetic acid and ammonia.

Hydrolysis of Ether

Ether hydrolysis involves hydrolysis of the ether linkage by strong acids or bases. The results are the molecular conversion into alcohols and/or alkyl halides. An example involves the hydrolysis of ethyl ether in acidic conditions:

(C2H5)2O + H2O + H+ → 2C2H5OH

In this reaction, ethyl ether reacts with water and a proton (from the acid) to form ethanol.

Hydrolysis vs Dehydration

In hydrolysis and dehydration both involve water but they occur in different directions and the process either generates or breaks chemical bonds for various reasons.

Hydrolysis

Dehydration

Hydrolysis is a chemical reaction, which takes place to result in the breaking of chemical bonds between the reactant and water molecules and in turn, formation of two or more new compounds.

Dehydration refers to a chemical reaction in which water molecules are extracted or stripped from a compound or the combined mixture of compounds.

In hydrolysis the bonds of the compounds are cleaved by using water molecules and so creates smaller molecules or ions.

In dehydration reactions elimination of a water molecule happen from the neighboring lines of atoms within a molecule. It produce a new covalent linkage between those atoms.

In hydrolysis reactions, one end of a divisible compound gains a hydroxyl group (-OH), while other ends obtain a hydrogen ion (H⁺).

In Dehydration larger molecules is synthesized from simpler ones. This gives rise to the formation of new bonds and the eliminating water as the one of product.

Hydrolysis leads to decomposition of the complex products into more simple ones.

Dehydration makes the compounds with a more massive molecular weight from certain molecules that are smaller by joining two simpler molecules and eliminating water moleculues.

Examples are of hydrolysis reactions include the splitting of esters into carboxylic acids and alcohols, the disintegration of polysaccharides into monosaccharides.

Dehydration Reactions example include the formation of polymers like proteins, nucleic acids and carbohydrates through the joining of monomers as water molecules are removed to form long chains or complexes.

Difference between Hydrolysis and Hydration

Hydrolysis and hydration are both chemical processes involving water, but they are fundamentally different in terms of their mechanisms and outcomes. The difference between hydrolysis and hydration is tabulated below:

Basis

Hydrolysis

Hydration

Definition

Hydrolysis is a chemical reaction, where the compound splits into two or more fragments due to splitting of chemical bonds within the compound.

Hydration occurs when water molecules form a complex with other molecules or ions of the substance without inducing a chemical reaction.

Type of Process

In hydrolysis, water is an agent of causing a reaction where the covalent bonds within a compound are broken.

In hydration water molecules move around the center of the solvent. The water molecules do not change their state with this process, but they protect the solute particles.

Outcome

Hydrolysis divides that same complex compound into a simple products.

Hydration does not modify the chemical composition of the solute. It attach the hydrate form, which enhance the solubility of the solute particles in water.

Chemical Change

Hydrolysis process is a chemical change which activated the breakage of chemical bonds and formation of new compounds.

Water hydrolysis causes no chemical reactions. It is a physical phenomenon involving water molecules and dissolved substance particles into a hydrosphere.

Biological Significance

Hydrolysis is the integral backbone of all biological processes, for instance, digestion, where macromolecules are broken down into smaller pieces (active form) to be utilized efficiently.

Hydration becomes vital for the required functions of one’s body, its proteins and enzymes to do their work perfectly.

Reversibility

It is possible for hydrolysis reactions to be reversed under certain conditions because products of hydrolysis are able to combine resulting in the regeneration of the initial compounds.

Hydration is reversible but it is energy consuming. The more solute particles become hydrated, the more they do not come out of the water unless removed in other ways entirely.

Examples

Esters react with water to yield carboxylic acid and alcohol. Polysaccharides are hydrolyzed into constituent monosaccharides.

Solubility into water is an example of the hydration. NaCl dissolves and the sodium ions form hydrates (the union of the solvents and the solute), and chloride ions will also be formed.

Applications of Hydrolysis

Hydrolysis has numerous applications in various fields. The applications of hydrolysis are mentioned below:

  • Digestion: Hydrolysis is responsible for breaking down complicated food components to then receive the body. In saliva, gastric juices and secretions of the intestines enzymes break down carbohydrates proteins and fats (using hydrolytic reactions).
  • Chemical Synthesis: The method of hydrolysis is commonly used in laboratory settings in synthesizing smaller molecule to a more convenient sized parts. This is a process in which these fragments are used as building blocks that can be used to synthesize these different compounds.
  • Environmental Processes: Decomposition of the organics by means of hydrolysis is one of the processes found in nature. For instance, the microbial enzymes that break down the cellulose a crucial part of the cell wall of higher plants contribute to the further decomposition of plants in soil.
  • Industrial Processes: Hydrolysis is a crucial in industrial areas. For example, in the biodiesel industry where the triglycerides in vegetable oils and animal fats are hydrolyzed to give fatty acids and glycerol.

Hydrolysis Frequently Asked Questions

What is hydrolysis?

Hydrolysis is a chemical reaction wherein a compound undergoes reaction with water, causing the breaking of one or multiple chemical bonds within the compound and the formation of two or more simpler compounds or ions.

What is a hydrolysis reaction?

The hydrolysis reaction is a chemical process where a compound undergoes a reaction with water in such a way that the old chemical bonds are torn which is followed by the formation of several new or compounds. Hydrolysis reaction is given as AB + H2O → AH + BOH

What is Example of hydrolysis reaction?

An example of a hydrolysis reaction is the breakdown of sucrose (table sugar) into glucose and fructose:

C12H22O11 + H2O → C6H12O6 + C6H12O6

What are different types of hydrolysis?

The main types of hydrolysis include, acid hydrolysis, base hydrolysis, enzymatic hydrolysis and salt hydrolysis. They comprise various catalysts and reaction conditions.

What is acid hydrolysis?

Acid hydrolysis is a type of hydrolysis in which catalyst donates protons. As a result of this, bonds in the compound break. This often occurs in biological systems and industrial processes.

What is base hydrolysis?

Base hydrolysis takes place under basic conditions which result in the splitting of bond by the hydroxide ions from a base. Saponification is the hydrolysis of esters by a base.

What is enzymatic hydrolysis?

Enzymatic hydrolysis encompasses the numbering of biocatalysts known as enzymes which are used to hydrolyze particular connections in organic molecules. Enzymes are very specific and highly productive in hydrolysis reactions.

What is difference between hydrolysis and dehydration?

The main difference between hydrolysis and dehydration is that hydrolysis breaks down complex molecule into simple one by reaction with water while dehydration combines simpler molecules into larger one by eliminating water molecule