NCERT Solutions Class 12 Chemistry - Chapter 6 Haloalkanes and Haloarenes - PDF Download

NCERT Solutions for class 12th chemistry chapter 6 Haloalkanes and Haloarenes given here are based on the latest CBSE syllabus. The NCERT solutions for class 12th chemistry mainly consist of the answers to the exercises as well as important questions in NCERT textbook. Please refer to these solutions to know the correct ways to answer and solve these questions.

eSaral’s subject experts have prepared and solved the NCERT solutions for Class 12 chemistry. These solutions are presented in easy language for well understanding. Students can use it anywhere and anytime as their key resource material.

Once you finish this unit, you will be able to

• name haloalkanes and haloarenes from their IUPAC nomenclature

• describe the reactions that are involved in the preparation of halos and haloarenes

• conformate the structures of haloalkane and haloarene with the various types of reactions related with haloalkanes and haloarenes.

• use stereochemistry as a means of understanding the reaction mechanism

• recognize the uses of organo-metals

• focus on the environmental effects of polyhalogen compounds.

Sections Covered in Chapter 6 - Haloalkanes and Haloarenes

6.1 Classification: 

The Haloalkanes and the Haloarenes can be divided into the following categories:

• On the basis of number of halogen atoms in the compound

• Compounds containing sp3C-X bond (X= F, Cl, Br, I)

• Compounds containing sp2C-X bond

6.2 Nomenclature: 

The haloalkane and haloarene nomenclature is based on the IUPAC nomenclature rules. The IUPAC nomenclature allows for the classification of haloalkanes and haloarene based on their molecular structure and the presence or absence of halogen atoms.

6.3 Nature of C-X bond: 

In haloalkanes and haloarenes, the C-X bond is polar. The halogen atom is more electropositive than the carbon, so the halogen has a partial negative charge and the carbon a partial positive charge. The strength of the bond depends on the identity of the halogen. The strongest bond is formed by fluorine, while the weakest bond is formed by iodine. Because of their reactivity, halide and halide bonds are involved in many organic reactions, especially in nucleophile substitution, elimination and coupling reactions.

6.4 Methods of Preparation of Haloalkanes:

Haloalkanes can be prepared through several methods, including:

• From Alcohols

• From Hydrocarbons

• Halogen Exchange

6.5 Preparation of Haloarenes: 

Haloarenes can be prepared through several methods, including:

• From hydrocarbons by electrophilic substitution

• From amines by sandmeyer’s reaction

6.6 Physical Properties: 

Alkyl halide is colourless when pure, bromide and iodide are colourless when exposed to light, many volatile halogen compounds have a sweet smell. Melting and boiling points, Solubility and density of different haloalkanes and haloarenes are discussed in this section.

6.7 Chemical Reactions:

Haloalkanes reactions can be classified as follows:

1. Nucleophilic substitution

2. Elimination reactions

3. Reaction with metals

The reactions of haloarenes may be divided into the following categories: 

1. Nucleophilic substitution

2. Electrophilic substitution reactions

3. Reaction with metals

6.8 Polyhalogen Compounds:

Polyhalogen compounds are carbon compounds with more than 1 halogen atom. Most of these compounds are used in industrial and agricultural applications. Some Polyhalogen compounds are described in this section are listed below.

• Dichloromethane (Methylene chloride)

• Trichloromethane (Chloroform)

• Triiodomethane (Iodoform)

• Tetrachloromethane (Carbon tetrachloride)

• Freons

• p,p’-Dichlorodiphenyltrichloroethane(DDT)

Key Features of Class 12 Chemistry Chapter 6 NCERT Solutions

• Alkyl/Aryl halides can be classified as mono halides, di halides, tri halides, tetra halides, etc. depending on whether they have one, two, or more halogens in their structure. Halogens are electronegative, so the carbon halide bond is polarised. There is a partial positive charge on the carbon and a partial negative charge on the halogen.

• The preparation of alkyl halides is by the halogenation of the free radical alkanes, the addition of halogen acids to the alkenes, the replacement of the –OH group of the alcohols by halogens using phosphorus halides or thionyl chloride, or halogen acids, and the preparation of Aryl halides by the electrophilic substitution of arenes. The preparation of fluorides and iodides is best done by the halogen exchange method.

• Organo-alkanes have higher boiling points than the corresponding hydrocarbons due to the strong dipole-dipole and Van der Waals forces of attraction. They are slightly water soluble, but completely water soluble in organic solvents.

• Polyhalogen compounds have a wide range of industrial applications, including but not limited to dichloromethanes, chloroforms, iodoforms, carbon tetrachlorides, freon and dioxins. However, some of these compounds are difficult to break down and can even lead to depletion of ozone layers, thus posing environmental risks.

Benefits of NCERT Solutions for Class 12 Chemistry Chapter 6 PDF Download 

Whether you’re getting ready for your exams or looking to enhance your knowledge of the subject, NCERT Solutions for class 12 chemistry chapter “haloalkane and haloarene” provide several advantages. There are few key advantages which are mentioned below:

• Comprehensive coverage: NCERT solutions explain the entire syllabus in a systematic way so that students don’t miss any important concepts in the chapter. NCERT solutions explain all the important topics in the chapter in a systematic manner.

• Clarity and Simplicity: The solutions are presented in a straightforward and easy-to-understand way. Complex topics are presented in a way that makes it easy for students to understand. Simple language and step by step explanations make it easier for students to understand the concepts.

• Correct and authentic information: NCERT solutions are prepared by experts in the subject matter. This ensures that the information provided is correct and authentic. Students can trust NCERT solutions to answer their questions correctly.

• Practice questions: The solutions include practice questions and practice exercises that students can use to test their knowledge of a particular chapter. These practice questions help to strengthen the concepts and improve problem solving skills.

• Exam preparation: The NCERT Solutions are an excellent tool for exam preparation. Not only do they help you understand the concepts, but they also provide solutions to the questions which are likely to be included in the exam.

• Time management: With the help of NCERT Solutions, you can easily manage your study time. The solutions help you understand the topics clearly, so you can focus on the important areas and avoid any unnecessary distractions.

Frequently Asked Questions

Question 1: what are haloalkanes and haloarenes?

Answer 1: Carbon-halogen (C-X)-bonded organic compounds are haloalkanes, where X stands for a halogen (e.g. fluorine, chlorine, bromine or iodine). Aromatic haloarene compounds are halaines with at least 1 halogen atom to the aromatic ring.

Question 2: What are the physical properties of haloalkanes and haloarenes?

Answer 2: The boiling and melting points of haloalkanes and halarenes are typically higher than those of their parent alkane and arenes, due to the formation of polar c- X bonds. The solubility of these compounds in water decreases as the carbon chain length increases due to their hydrophobic properties.