Types of Alcohols

What is Alcohol?

Alcohols are those organic compounds which are characterized by the presence of one, two or more hydroxyl groups (−OH) that are attached to the carbon atom in an alkyl group or hydrocarbon chain.

These alcohols are considered to be as the derivatives of water where one among the hydrogen atoms are replaced by alkyl group, which is typically represented by the letter R in an organic structure. Alcohol also comes in different structures and forms.

Alcohols are known to be one among most of the commonly occurring organic compounds. These are utilized in the form of sweeteners, preparation of perfumes, and sometimes in the process of synthesizing other compounds, wherein some others are abundantly manufactured in organic chemicals coming in various industries.

Related Topics

• Nomenclature of Alcohols
• Preparation of Alcohols
• Physical and Chemical Properties of Alcohols
• Identification of Primary, Secondary and Tertiary Alcohols
• Dehydration of Alcohols
• Uses of Methanol and Ethanol

Main Types of Alcohols

Alcohols are differentiated based upon the presence of the hydroxyl group attached. The location of this hydroxyl group as well will change the physical and chemical properties of any alcohol.

There are three types of alcohol. Alcohols are classified as primary, secondary or tertiary alcohols.

Types of Alcohols

The classification is done in accordance with the carbon atom of an alkyl group is attached to the hydroxyl group. Most of the alcohols are known to be colourless liquids or even are said to behave as solid at room temperatures. Alcohols with less molecular weight are said to be highly soluble in water; and with their increase in molecular weight, they tend to become less soluble and their vapour pressures, boiling points, densities, and the viscosities to increase.

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Let us study in brief about the types of alcohols.

1. Primary Alcohols

Primary alcohols are those alcohols where the carbon atom of the hydroxyl group (OH) is attached to only one single alkyl group. Some examples of these primary alcohols include Methanol (propanol), ethanol, etc. The complexity of this alkyl chain is unrelated to the classification of any alcohol considered as primary. The existence of only one linkage among –OH group and an alkyl group and the thing that qualifies any alcohol as a primary.

Primary Alcohols

2. Secondary Alcohols

Secondary alcohols are those where the carbon atom of the hydroxyl group is attached to two alkyl groups on either side. The two alkyl groups present may be either structurally identical or even different. Some examples of secondary alcohols are given below.

Secondary Alcohols

3. Tertiary Alcohols

Tertiary alcohols are those which feature a hydroxyl group attached to the carbon atom which is connected to 3- alkyl groups. The physical properties of these alcohols mainly depend on their structure. The presence of this -OH group allows the alcohols in the formation of hydrogen bonds with their neighbouring atoms. The bonds formed are weak, and this bond makes the boiling points of alcohols higher than its alkanes. Examples of tertiary alcohols include-

Uses of Alcohols

There are several uses of alcohols. Some are listed below.

• Alcohols are consumed as beverages where the alcohols specifically consist of 30–40 per cent of ethanol by volume.
• These are used as an anti-freezing agent with a mixture of a solution containing ethylene glycol dissolved in water.
• Alcohol ethanol is used as an antiseptic agent.
• Some alcohols are used as fuels in internal combustion engines like the methanol.
• In the field of medicine, a few of them are used as preservatives for the specimens in laboratories.

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