Learn
Games

8.9.4.1 - Halogenation

Interactive Audio Lesson

Listen to a student-teacher conversation explaining the topic in a relatable way.

Introduction to the Halogenation Reaction

Unlock Audio Lesson

Signup and Enroll to the course for listening the Audio Lesson

Teacher
Teacher

Today, we're covering halogenation in carboxylic acids. Can anyone tell me what halogenation involves?

Student 1
Student 1

Is it when we introduce halogen atoms into a compound?

Teacher
Teacher

Exactly! In this case, we introduce halogen atoms into carboxylic acids. Now, which part of the carboxylic acids do we typically target?

Student 2
Student 2

The a-hydrogens?

Teacher
Teacher

Correct! The a-hydrogens of carboxylic acids are reactive and can be substituted easily. We'll call this the Hell-Volhard-Zelinsky reaction.

Mechanism of Halogenation

Unlock Audio Lesson

Signup and Enroll to the course for listening the Audio Lesson

Teacher
Teacher

Let's discuss how the mechanism works. In the presence of red phosphorus, halogens can substitute these a-hydrogens. Can someone explain why red phosphorus is used?

Student 3
Student 3

Does it help in activating the halogen for the reaction?

Teacher
Teacher

Yes! Red phosphorus creates the right conditions for the halogen to effectively react. So, what are the outcomes of this halogenation?

Student 4
Student 4

We get a-haolocarboxylic acids as products.

Teacher
Teacher

Excellent! This transformation changes both the reactivity and properties of the original carboxylic acid.

Applications of Halogenated Carboxylic Acids

Unlock Audio Lesson

Signup and Enroll to the course for listening the Audio Lesson

Teacher
Teacher

Now that we've covered the basics, why do we perform halogenation? What applications can arise from halogenated carboxylic acids?

Student 1
Student 1

They could be used for further reactions, right? Like making esters or amides?

Teacher
Teacher

Exactly! Halogenated compounds can serve as intermediates in various syntheses. This specificity can tailor properties for diverse applications in pharmaceuticals and materials science.

Student 2
Student 2

So, modifying the halogen can affect the efficacy of these compounds?

Teacher
Teacher

Absolutely! Each halogen can influence the final product's reactivity.

Key Summary of the Reaction

Unlock Audio Lesson

Signup and Enroll to the course for listening the Audio Lesson

Teacher
Teacher

To sum up today’s lesson, what is the main point of the Hell-Volhard-Zelinsky reaction?

Student 3
Student 3

It’s a method to add halogens to a-hydrogens on carboxylic acids.

Teacher
Teacher

Great! And how does this relate to organic synthesis?

Student 4
Student 4

It provides pathways to synthesize a wide range of other chemicals!

Teacher
Teacher

Exactly! Keep in mind, the a-hydrogen is key. Excellent work today! Remember the significance of the halogenation reaction.

Introduction & Overview

Read a summary of the section's main ideas. Choose from Basic, Medium, or Detailed.

Quick Overview

This section discusses the process of halogenation in carboxylic acids, particularly focusing on how a-hydrogens are substituted.

Standard

Halogenation refers to the substitution of a-hydrogens in carboxylic acids with halogen atoms (chlorine or bromine) in the presence of red phosphorus. This is a key reaction known as the Hell-Volhard-Zelinsky reaction, which emphasizes the importance of a-hydrogens in determining the reaction's outcome.

Detailed

Halogenation of Carboxylic Acids

This section specifically addresses the halogenation of carboxylic acids, which undergo substitution reactions involving their a-hydrogens. When carboxylic acids that contain an a-hydrogen are treated with chlorine or bromine in the presence of a small amount of red phosphorus, a-haolocarboxylic acids are formed. This reaction is known as the Hell-Volhard-Zelinsky reaction.

Significance

The Hell-Volhard-Zelinsky reaction is important for introducing halogen substituents on organic compounds, which can then be subjected to further reactions, affecting the physical and chemical properties of the resultant compounds. This process not only demonstrates the reactivity of carboxylic acids but also highlights the functionality of the a-hydrogens present in these molecules.

Youtube Videos

Electrophilic Substitution Reaction - Aldehydes, Ketones & Carboxylic Acids | Class 12 Chemistry Ch8
Electrophilic Substitution Reaction - Aldehydes, Ketones & Carboxylic Acids | Class 12 Chemistry Ch8
Aldehydes,Ketones & Carboxylic Acids Class 12 Chemistry Chapter 8 One Shot | New NCERT CBSE
Aldehydes,Ketones & Carboxylic Acids Class 12 Chemistry Chapter 8 One Shot | New NCERT CBSE
12. ALDEHYDES KETONES AND CARBOXYLIC ACIDS | Lecture - 4 | Eklavya 5.0 | Class 12 Chemistry #mhtcet
12. ALDEHYDES KETONES AND CARBOXYLIC ACIDS | Lecture - 4 | Eklavya 5.0 | Class 12 Chemistry #mhtcet
#Aldehyde ketone carboxylic acid *1#
#Aldehyde ketone carboxylic acid *1#
Aldehydes ketone and carboxylic acids ncert one shot // chapter 12 chemistry class 12 ncert term 2
Aldehydes ketone and carboxylic acids ncert one shot // chapter 12 chemistry class 12 ncert term 2
12. ALDEHYDES KETONES AND CARBOXYLIC ACIDS | Lecture - 3 | Eklavya 5.0 | Class 12 Chemistry #mhtcet
12. ALDEHYDES KETONES AND CARBOXYLIC ACIDS | Lecture - 3 | Eklavya 5.0 | Class 12 Chemistry #mhtcet
Aldehydes Ketones and Carboxylic acids One Shot | Class12 Chemistry Chapter 12 | CBSE JEE NEET
Aldehydes Ketones and Carboxylic acids One Shot | Class12 Chemistry Chapter 12 | CBSE JEE NEET
class 12 Aldehyde ketones and carboxylic acid (part 7)
class 12 Aldehyde ketones and carboxylic acid (part 7)
12. ALDEHYDES KETONES AND CARBOXYLIC ACIDS | Lecture - 2 | Eklavya 5.0 | Class 12 Chemistry #mhtcet
12. ALDEHYDES KETONES AND CARBOXYLIC ACIDS | Lecture - 2 | Eklavya 5.0 | Class 12 Chemistry #mhtcet
Aldehydes, ketones and carboxylic acids
Aldehydes, ketones and carboxylic acids

Audio Book

Dive deep into the subject with an immersive audiobook experience.

Overview of Halogenation

Unlock Audio Book

Signup and Enroll to the course for listening the Audio Book

Carboxylic acids having an a-hydrogen are halogenated at the a-position on treatment with chlorine or bromine in the presence of small amount of red phosphorus to give a-halocarboxylic acids. The reaction is known as Hell-Volhard-Zelinsky reaction.

Detailed Explanation

Halogenation is a chemical reaction where halogens (like chlorine or bromine) are introduced into a compound. In the case of carboxylic acids with an a-hydrogen, halogenation occurs specifically at the alpha position (the carbon next to the carboxyl group). This reaction requires a catalyst, specifically red phosphorus, which facilitates the process. This is referred to as the Hell-Volhard-Zelinsky (HVZ) reaction, a significant method for modifying carboxylic acids to introduce halogen atoms, thus creating a-halocarboxylic acids. Using red phosphorus is crucial as it helps in activating the halogen for the reaction.

Examples & Analogies

You can think of this reaction like a tailor altering a dress. Just as a tailor adds or modifies a feature of the garment (like a pocket or embellishment), the halogenation process adds a halogen atom to a specific position in the carboxylic acid, changing its properties and potential uses in organic chemistry.

Importance of Halogenated Carboxylic Acids

Unlock Audio Book

Signup and Enroll to the course for listening the Audio Book

The halogenated products, a-halocarboxylic acids, are important intermediates in organic synthesis and can lead to the formation of various other chemical compounds.

Detailed Explanation

The products of halogenation, namely the a-halocarboxylic acids, serve as valuable intermediates in organic synthesis. This means they are often used as building blocks to create more complex molecules in the lab. For instance, these halogenated acids can be transformed into various pharmaceuticals, agrochemicals, and dyes. Their reactivity also allows them to undergo further reactions that generate a wide range of useful compounds in industry.

Examples & Analogies

Imagine building a LEGO castle. Each halogenated carboxylic acid is like a unique LEGO piece that can connect with other pieces (different reactants) to form more intricate structures (complex compounds). Just as certain pieces connect better based on their shapes, these halogenated acids are designed to fit into various chemical reactions, yielding products that are essential for multiple applications.

Definitions & Key Concepts

Learn essential terms and foundational ideas that form the basis of the topic.

Key Concepts

  • Halogenation: The introduction of halogens into organic compounds, specifically targeting a-hydrogens of carboxylic acids.

  • a-Hydrogens: Reactive hydrogen atoms that, when halogenated, transform the properties and reactions of carboxylic acids.

  • Hell-Volhard-Zelinsky Reaction: A critical method for halogenating carboxylic acids that underlines their chemical reactivity.

Examples & Real-Life Applications

See how the concepts apply in real-world scenarios to understand their practical implications.

Examples

  • When acetic acid (a carboxylic acid with one a-hydrogen) is treated with bromine and red phosphorus, bromoacetic acid (a-halocarboxylic acid) can be synthesized.

  • Chloroacetic acid, formed from acetic acid through the Hell-Volhard-Zelinsky reaction, serves as a precursor in many organic syntheses.

Memory Aids

Use mnemonics, acronyms, or visual cues to help remember key information more easily.

🎵 Rhymes Time

  • To halogenate, we need a tale, a-hydrogens fall and halogens sail.

📖 Fascinating Stories

  • Imagine a lab where acetic acid meets a bromine friend, and with a sprinkle of red phosphorus, they make a magical blend.

🧠 Other Memory Gems

  • Remember: 'H-A-Stop' means Halogenation, a-hydrogens substitute, causing a reaction.

🎯 Super Acronyms

HALO

  • Hydrocarbons Attractand Lead to halogenation Outcomes.

Flash Cards

Review key concepts with flashcards.

Glossary of Terms

Review the Definitions for terms.

  • Term: Halogenation

    Definition:

    The process of introducing halogen atoms into a compound.

  • Term: Carboxylic Acid

    Definition:

    An organic compound containing a carboxyl (-COOH) functional group.

  • Term: aHydrogen

    Definition:

    Hydrogens attached to the carbon atom adjacent to the carboxyl group in a carboxylic acid.

  • Term: HellVolhardZelinsky Reaction

    Definition:

    A reaction involving the substitution of a-hydrogens in carboxylic acids to yield a-haolocarboxylic acids.