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Substitution Reaction

In this lecture we are going to learn about substitution reaction,substitution reaction definition and examples and also what nucleophilic substitution reaction is used for.

Alcohols are chemical molecules with one, two, or more hydroxyl groups (OH) linked to each carbon atom in an alkyl group or hydrocarbon chain.

These alcohols are water derivatives in which one of the hydrogen atoms is replaced by an alkyl group, which in an organic structure is commonly indicated by the symbol R. Alcohol is also available in a variety of shapes and forms.

Alcohol is known to be one of the most common chemical substances on the planet. 

These are used as sweeteners, in the manufacturing of perfumes, and occasionally in the process of synthesising other compounds, while others are abundantly produced in organic chemicals used in numerous sectors.

The Different Types of Alcohols

Alcohols are classified according to whether or not they have a hydroxyl group connected to them. The physical and chemical properties of any alcohol are affected by the placement of this hydroxyl group.

There are three different kinds of alcohol. Alcohols are divided into three categories: primary, secondary, and tertiary.

Alcohols of Various Types

The hydroxyl group is classified according to where an alkyl group’s carbon atom is connected to the hydroxyl group. At room temperatures, the majority of alcohols are described as colourless liquids or even solids. 

Alcohols with a low molecular weight are considered to be highly soluble in water, while those with a higher molecular weight become less soluble and have higher vapour pressures, boiling temperatures, densities, and viscosities.

1. Alcohols that are primary in nature

Primary alcohols are those in which the hydroxyl group’s carbon atom (OH) is connected to only one alkyl group. Methanol (propanol), ethanol, and other main alcohols are examples. 

The intricacy of this alkyl chain has nothing to do with the classification of any primary alcohol. The fact that there is just one link between the –OH group and an alkyl group classifies every alcohol as a primary.

2. Alcohols with a secondary function

Secondary alcohols are ones in which the hydroxyl group’s carbon atom is joined to two alkyl groups on either side. 

The two alkyl groups present could be structurally similar or perhaps dissimilar. The following are some instances of secondary alcohols.

Examples :- 2 – propanol and 2 – butanol.

3.Tertiary Alcohols are the third kind of alcohol.

Tertiary alcohols have a hydroxyl group bonded to the carbon atom and are linked to three alkyl groups. The structure of these alcohols determines their physical properties.

 Because of the existence of this -OH group, alcohols can establish hydrogen bonds with their neighbouring atoms. Because the bonds formed are weak, the boiling points of alcohols are greater than those of alkanes.

For example (CH3)3COH is a tertiary alcohol

Alcoholic preparation

Alcohols can be used in a variety of ways. The following are a few examples.

Alcohols are ingested in the form of beverages that contain 30–40% ethanol by volume.

These are made from a solution of ethylene glycol dissolved in water and are used as an anti-freezing agent.

Alcohol, often known as ethanol, is used as an antiseptic.

Some alcohols, such as methanol, are utilised as fuels in internal combustion engines.

A couple of them are employed as preservatives for laboratory specimens in the medical industry.

Conclusion

Alcohols are chemical molecules with one, two, or more hydroxyl groups (OH) linked to each carbon atom in an alkyl group or hydrocarbon chain.

These alcohols are water derivatives in which one of the hydrogen atoms is replaced by an alkyl group, which in an organic structure is commonly indicated by the symbol R. Alcohol is also available in a variety of shapes and forms.

 In Grignard reagents, ether is utilised as an anaesthetic, a cooling agent, and an inert solvent.

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Frequently Asked Questions

Get answers to the most common queries related to the JEE Examination Preparation.

Do substitution reactions cause bonds to be broken?

Ans: Substitution reactions require breaking one sigma bond and establishing another sigma bond, regardless o...Read full

How does a substitution reaction happen when a catalyst is present?

Ans : When methane combines with chlorine gas, UV light can help speed up the ...Read full

Does the substitution reaction redox?

Ans:- Yes, it’s redox.