Summary of شرح أسطوري لمشتقات الهيدروكربونات|| 3 ثانوي 2024 || مستر خالد صقر

Summary of Main Ideas and Concepts

1. Introduction to Hydrocarbon Derivatives

• Hydrocarbon derivatives are organic compounds containing carbon and hydrogen plus other elements like oxygen or nitrogen.
• Functional groups (or effective groups) are small parts of molecules responsible for their characteristic properties.
• Classification of organic compounds is based on their functional groups rather than physical properties like color or smell.

2. Classification of Hydrocarbon Derivatives

• Major classes covered:
  • Alcohols (Kohls)
  • Phenols
  • Ethers
  • Aldehydes
  • Ketones
  • Carboxylic acids
  • Esters
  • Amines
• Differences between Alcohols and Phenols:
  • Alcohols: hydroxyl group (-OH) attached to an aliphatic (alkyl) group.
  • Phenols: hydroxyl group attached directly to an aromatic (benzene) ring.

3. Alcohols (Kohls)

• General formula for monohydric Alcohols: CnH2n+1OH.
• Naming Alcohols:
  • Common names: alkyl + "alcohol" (e.g., methyl alcohol, ethyl alcohol).
  • IUPAC names: based on the longest carbon chain, numbering from the end nearest the hydroxyl group, suffix "-ol" (e.g., ethanol, propanol).
• Special naming rules for branched Alcohols: use "iso-" prefix when a carbon atom carries a methyl group.
• Classification of Alcohols based on:
  • Number of hydroxyl groups: mono-, di-, tri-, polyhydric Alcohols.
  • Position of hydroxyl-bearing carbon: primary (1°), secondary (2°), tertiary (3°).

4. Physical Properties of Alcohols

• Alcohols have higher boiling points than hydrocarbons due to hydrogen bonding between hydroxyl groups.
• Solubility in water decreases as the carbon chain length increases.
• More hydroxyl groups increase boiling point and solubility.

5. Preparation of Alcohols

• Industrial methods:
  • Fermentation of sugars (e.g., molasses → glucose/fructose → ethanol via yeast enzyme zymase).
  • Hydration of alkenes (e.g., ethene + water in presence of sulfuric acid → ethanol).
  • Reaction of alkyl halides with aqueous alkali (alkyl halide + KOH → alcohol).

6. Chemical Properties of Alcohols

• Reactivity divided into:
  • Reactions specific to hydroxyl group (e.g., reaction with active metals like sodium to form alkoxides and hydrogen gas).
  • Reactions involving the carbon atom attached to hydroxyl (oxidation).
  • Esterification with organic acids (forming esters and water).
  • Reaction with halogen acids to form alkyl halides.
• Acidity: Alcohols are weakly acidic, showing acidity mainly in reaction with active metals.
• Oxidation:
  • Primary Alcohols oxidize in two steps: to Aldehydes (acetaldehyde) then to Carboxylic acids (acetic acid).
  • Secondary Alcohols oxidize to Ketones (acetone) in one step.
  • Tertiary Alcohols generally do not oxidize under mild conditions.

7. Isomerism in Alcohols and Related Compounds

• Alcohols and Ethers can be isomers with the same molecular formula but different structures.
• Examples of isomerism with C3H8O compounds (propanol isomers and Ethers).

8. Phenols

• Phenols are hydroxyl derivatives of aromatic compounds (benzene ring with -OH).
• Phenol (hydroxybenzene) and its derivatives like catechol and pyrogallol.
• Phenol is more acidic than alcohol due to resonance stabilization of the phenoxide ion.
• Preparation of phenol:
  • Fractional distillation of coal tar.
  • Hydrolysis of chlorobenzene under alkaline conditions at high temperature and pressure.
• Chemical properties:
  • Reacts with active metals and metal hydroxides (more acidic than Alcohols).
  • Does not react with halogen acids like Alcohols do.
  • Undergoes nitration to form picric acid (trinitrophenol), used as an explosive and antiseptic.
  • Polymerization with formaldehyde to form Bakelite, a heat-resistant plastic used in electrical insulators and fire extinguishers.

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