What is the Hydroxyl Group?

It is a functional group formed by an oxygen atom and a hydrogen atom and has a monovalent valence.

The hydroxyl group is divided into several subcategories. Among these categories are alcohols, amphiboles, carbohydrates, carboxylic acids, cellulose, phenols and some plastics.


The Formation of Hydroxyl Groups

As stated, hydroxyl groups are simple structures that consist of a hydrogen atom and an oxygen atom. Since the oxygen molecule usually forms a double bond with other atoms, when one of these atoms is removed, a hydroxyl functional group can be formed. Let's take the most common and simple example, water molecules. Consisting of two hydrogen atoms and one oxygen atom, when the water molecule loses a hydrogen atom, a hydroxyl functional group, or -OH, is formed.


Alcohol and Phenols

When a hydroxyl group comes into contact with an alkane structure, a reaction occurs to form an alcohol such as ethanol. When it is with an aryl ring that the hydroxyl group comes into contact, a phenol is obtained. Being very common in nature, alcohols and phenols have a wide variety of physical and chemical properties that are useful.



This group of hydrated minerals is found mainly in metamorphic rocks and consists of hydroxyl groups in their structure. For information purposes, amphiboles are referred to as hydrated silicates that are only found in hydrous environments. Moreover, the presence of hydroxyl groups in these minerals decreases their thermal resistance.


The Carbohydrate

Carbohydrates are the most abundant and widespread organic substances in nature. Being essential compounds for living beings, carbohydrates are formed by plants through photosynthesis. In fact, carbohydrates are composed of hydroxyl groups and carbon atoms.



Some hydroxyl groups such as amides can form hydrogen bonds to form cellulose. Acting in a similar way to a certain polymer, cellulose is an organic compound that usually comes from plants. In fact, cellulose has been very popular in the water treatment industry. In fact, since the mid-1950s, cellulose acetate has been used in the manufacture of reverse osmosis membranes.


Hydroxyl groups

In other words, although hydroxyl groups are relatively simple in composition, their presence in a wide variety of compounds makes them a mainstay in the chemical composition of many compounds essential to life and to the proper functioning of many chemical reactions that occur naturally and synthetically.

In short, the compounds discussed above are among the most common with hydroxyl groups in their composition, but they are not the only ones. Indeed, there are many more such as certain plastics or certain acids.

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