Grade 12
  1. Solid state  1.1. Classification of solids  1.2. Crystal Lattice and Unit Cell  1.3. Packing Efficiency  1.4. Density of unit cell  1.5. Imperfections in solids (point and line defects)  1.6. Electrical Properties of Solids (Conductors, Insulators and Semiconductors)  1.7. Magnetic Properties of Solids (Diamagnetic, Paramagnetic and Ferromagnetic Materials)
  2. Solution  2.1. Types of Solutions (Homogeneous and Heterogeneous)  2.2. Expressing concentration of solutions (mass %, volume %, molarity, molality, normality, mole fraction)  2.3. Solubility of solids and gases in liquids (Henry's law)  2.4. Raoult's Law and Ideal and Non-Ideal Solutions  2.5. Syndrome properties  2.6. Abnormal molar mass and Van't Hoff factor
  3. Electrochemistry  3.1. Electrochemical cells (galvanic and electrolytic cells)  3.2. Galvanic cell and EMF of the cell  3.3. Standard electrode potential and electrochemical series  3.4. Nernst equation and its applications  3.5. Conductivity and electrolytic cells (specific, molar and equivalent conductivity)  3.6. Kohlrausch's law and its applications  3.7. Batteries (primary and secondary cells)  3.8. Corrosion and its prevention
  4. Chemical kinetics  4.1. Rate of chemical reaction  4.2. Factors affecting the reaction rate (concentration, temperature, catalyst, surface area)  4.3. Order and molecularity of the reaction  4.4. Integrated Rate Equations (Zero, First and Second Order)  4.5. Half-life of a reaction  4.6. Collision theory and activation energy  4.7. Arrhenius equation and its applications
  5. Surface chemistry  5.1. Adsorption and its types (Physicosorption and Chemisorption)  5.2. Catalysis and its types (homogeneous and heterogeneous)  5.3. Colloids and their properties (Tyndall effect, Brownian motion, coagulation)  5.4. Emulsions and gels  5.5. Applications of Colloids
  6. General principles and processes of separation of elements  6.1. Presence of metals and minerals  6.2. Concentration of ores (gravity separation, froth flotation, magnetic separation)  6.3. Extraction of raw metals (roasting, calcination, reduction)  6.4. Thermodynamic and electrochemical principles of metallurgy  6.5. Refining of metals
  7. P-block elements  7.1. Group 15 elements (nitrogen and phosphorus)  7.2. Group 16 Elements (Oxygen, Sulphur and their Compounds)  7.3. Group 17 Elements (Halogens and their Compounds)  7.4. Group 18 Elements  7.5. Properties and Trends in p-Block Elements  7.6. Important compounds of p-block elements (ammonia, phosphine, sulphuric acid, hydrochloric acid)  7.7. Interhalogen compounds and their applications
  8. d-block and f-block elements  8.1. General Properties of Transition Metals  8.2. Properties of Inner Transition Metals (Lanthanoids and Actinoids)  8.3. Lanthanoid and actinoid contractions  8.4. Coordination Chemistry of d-Block Elements
  9. Coordination compounds  9.1. Werner's theory and modern concepts  9.2. Coordination number and type of ligand  9.3. Nomenclature of Coordination Compounds  9.4. Isomerism (geometrical and optical) in coordination compounds  9.5. Bonding in Coordination Compounds (Valence Bond Theory and Crystal Field Theory)  9.6. Stability and applications of coordination compounds in medicine and industry
  10. Haloalkanes and haloarenes  10.1. Classification and nomenclature of haloalkanes and haloarenes  10.2. Physical and Chemical Properties of Haloalkanes and Haloarenes  10.3. Mechanism of Nucleophilic Substitution Reactions (SN1 and SN2)  10.4. Uses and environmental effects (ozone depletion, CFCs)
  11. Alcohol, phenol and ether  11.1. Structure and classification of alcohols, phenols and ethers  11.2. Preparation and properties of alcohols  11.3. Preparation and properties of phenol  11.4. Preparation and properties of ethers  11.5. Chemical Reactions and Uses
  12. Aldehydes, ketones and carboxylic acids  12.1. Structure and nomenclature in aldehydes, ketones and carboxylic acids  12.2. Preparation and properties of aldehydes and ketones  12.3. Chemical reactions in aldehydes, ketones and carboxylic acids (nucleophilic addition, oxidation and reduction)  12.4. Preparation and Properties of Carboxylic Acids  12.5. Chemical Reactions and Uses of Carboxylic Acids
  13. Nitrogen-containing organic compounds  13.1. Amines (classification, structure, basicity)  13.2. Preparation and properties of amines  13.3. Reactions of Amines (Diazotization, Carbylamine Reaction)  13.4. Diazonium salts and their applications in paint industry
  14.1. Carbohydrates (classification and properties)  14.2. Proteins (Structure and Function)  14.3. Enzymes (Mechanism and Function)  14.4. Nucleic acids (DNA and RNA)  14.5. Vitamins and hormones
  15. Polymer  15.1. Classification of Polymers (Addition, Condensation, Copolymers)  15.2. Types of polymerization (free radical, ionic, condensation)  15.3. Important Polymers and Their Uses  15.4. Biodegradable and non-biodegradable polymers
  16. Chemistry in Everyday Life  16.1. Drugs and their classification (analgesics, antipyretics, antibiotics, antacids)  16.2. Chemicals in food and cosmetics (preservatives, artificial sweeteners, antioxidants)  16.3. Cleaning agents and detergents (soaps, synthetic detergents, surfactants)  16.4. Environmental Chemistry (Pollution, Green Chemistry, Sustainable Chemistry)

Grade 12 → Haloalkanes and haloarenes ↓


Classification and nomenclature of haloalkanes and haloarenes


Haloalkanes and haloarenes are important classes of organic compounds. They are derived from hydrocarbons where one or more hydrogen atoms are replaced by halogen atoms. This substitution can significantly alter the properties and reactivities of the original hydrocarbon, making haloalkanes and haloarenes valuable in a variety of chemical applications.

Haloalkanes

Definition

Haloalkanes, also known as alkyl halides, are compounds in which one or more hydrogen atoms in aliphatic hydrocarbons are replaced by a halogen atom (fluorine, chlorine, bromine, or iodine). The general formula for haloalkanes is RX, where R is an alkyl group and X is a halogen.

Classification of haloalkanes

Haloalkanes can be classified based on several criteria:

1. Based on the number of halogen atoms

  • Monohaloalkane: Contains one halogen atom. Example: CH3Cl (chloromethane)
  • Dihaloalkane: Contains two halogen atoms. Example: CH2Cl2 (dichloromethane)
  • Trihaloalkane: It contains three halogen atoms. Example: CHCl3 (chloroform)
  • Tetrahaloalkane: Contains four halogen atoms. Example: CCl4 (carbon tetrachloride)
HH
|
H - C - C - Br
|
HH

2. Depending on the type of carbon atom bonded to the halogen

  • Primary (1°) alkyl halide: The halogen is attached to a primary carbon (a carbon atom bonded to only one other carbon). Example: CH3CH2Cl (ethyl chloride)
  • Secondary (2°) alkyl halide: The halogen is attached to a secondary carbon (a carbon atom bonded to two other carbons). Example: CH3CHClCH3 (2-chloropropane)
  • Tertiary (3°) alkyl halide: The halogen is attached to a tertiary carbon (a carbon atom bonded to three other carbons). Example: (CH3)3CCl (tert-butyl chloride)

3. Based on the type of halogen atom

  • Fluoroalkane: Contains fluorine. Example: CF3H (trifluoromethane)
  • Chloroalkanes: Contain chlorine. Example: CH3Cl (chloromethane)
  • Bromoalkane: Contains bromine. Example: CH2Br2 (dibromomethane)
  • Iodoalkane: Contains iodine. Example: CH3I (iodomethane)

Naming of haloalkanes

IUPAC nomenclature system

The International Union of Pure and Applied Chemistry (IUPAC) system is the most widely accepted method for naming haloalkanes. Naming involves several steps:

Steps of Naming

  1. Identify the longest continuous carbon chain in the compound that contains a halogen atom. This is the parent chain, and its name will be based on the number of carbon atoms it contains.
    • 1 carbon: methane
    • 2 carbons: ethane
    • 3 carbons: propane
    • 4 carbons: butane
    • 5 carbons: pentane
    • 6 carbons: hexane
  2. Locate and number the carbon atoms in the parent chain, starting at the end nearest the halogen group.
  3. Name the halogen substituents in alphabetical order, and specify their position on the parent chain with a number. Use prefixes such as "di-", "tri-", etc. for multiple identical substituents.
  4. Combine the names of the halogen substituents and the parent chain.

Example: CH3CHClCH2Br

- The longest chain has three carbon atoms: propane
- Numbering starts from the end nearest the halogen: 1-chloro, 3-bromo
- Alphabetical order: 1-Bromo-3-chloropropane

Common naming systems

The common naming system (also called trivial nomenclature) often uses the name of the halide followed by the name of the alkyl group.

Example: CH3Cl is called methyl chloride.

Haloarenes

Definition

Haloarenes, also known as aryl halides, are compounds in which one or more hydrogen atoms in aromatic hydrocarbons are replaced by halogen atoms. The general formula for haloarenes is Ar-X, where Ar is an aryl group and X is a halogen.

Classification of haloarenes

Haloarenes can be classified based on the orientation of the halogen atoms.

1. Mono-substituted haloarenes

These contain a halogen atom attached to an aromatic ring. Example: C6H5Cl (chlorobenzene)

/
|O|
/

2. Di-substituted haloarene

These contain two halogen atoms linked by an aromatic ring. These can be further classified depending upon the relative position:

  • Ortho-position: adjacent positions (1,2 positions). Example: 1,2-Dichlorobenzene
  • Meta-position: one carbon away (1,3 position). Example: 1,3-Dichlorobenzene
  • Para-position: The opposite side of the benzene ring (1,4 position). Example: 1,4-Dichlorobenzene

3. Tri or poly-substituted haloarenes

These contain three or more halogen atoms attached to an aromatic ring. The nomenclature will be according to the position and number of each substituent.

Naming of haloarenes

IUPAC nomenclature system

The IUPAC nomenclature for haloarenes is usually straightforward:

  • The parent name is the aromatic compound (usually benzene).
  • Name and number the substituted substances along with their respective positions.

Example: C6H4BrCl

- The original name is benzene.
- Bromine and chlorine are substituents, named alphabetically.
- Example name: 1-Bromo-2-chlorobenzene

Common naming system for haloarenes

As with haloalkanes, haloarenes may be named using common terminology, which often supersedes systematic names:

  • Example: C6H5Cl is named chlorobenzene in both systems.

Comparison of haloalkanes and haloarenes

Although haloalkanes and haloarenes are similar in some respects such as having halogen substituents, they differ due to the nature of the carbon chain (aliphatic vs aromatic) to which they are attached. For example, haloarenes are generally less reactive than haloalkanes due to the displacement of electrons in the aromatic ring which stabilizes the bond between carbon and halogen.

Concluding notes

Understanding the classification and nomenclature of haloalkanes and haloarenes is essential for identifying these compounds in organic chemistry and communicating about them effectively. They serve as basic building blocks in many synthetic processes, pharmaceuticals, and industrial applications.


Grade 12 → 10.1


U
username
0%
completed in Grade 12

← Prev (10)
Haloalkanes and haloarenes
Next (10.2) →
Physical and Chemical Properties of Haloalkanes and Haloarenes

Comments 



Classification and nomenclature of haloalkanes and haloarenes

https://www.chemistryelite.com/g12/10.1?ceal=en