Properties and Chemical Reactions of Alcohols, Ethers, and Halides

Physical Properties of Alcohols

• State: Lower alcohols are liquids; higher alcohols are solids.
• Density: Less dense than water.
• Boiling Points: Higher than corresponding alkanes.
• Solubility: Decreases as the number of carbon atoms increases.

Common Alcohols

• Methanol: CH₃OH
• Ethanol: CH₃CH₂OH

Ethanol Production

• Natural: C₆H₁₂O₆ → 2CH₃CH₂OH + 2CO₂
• Artificial: CH₂=CH₂ + H₂O → CH₃CH₂OH

Chemical Properties of Alcohols

Alcohols undergo oxidation reactions that distinguish primary, secondary, and tertiary structures:

• Primary Alcohols: Oxidize to form aldehydes (e.g., CH₃CH₂OH + ½O₂ → CH₃CHO + H₂O).
• Secondary Alcohols: Oxidize to form ketones (e.g., CH₃-CHOH-CH₃ + O₂ → CH₃-CO-CH₃ + H₂O).
• Tertiary Alcohols: Undergo chain cleavage.

Applications and Derivatives

Phenol and Glycerin

• Phenol: Used as a 1% antiseptic and disinfectant solution.
• Glycerin: Reacts with nitric acid to form nitroglycerin (propane-1,2,3-triol), a dense liquid found in animal and vegetable fats.

Ethers

Ethers are colorless, highly flammable, and insoluble in water but soluble in organic solvents. They were historically used as anesthetics.

• Ethyl Ether: CH₃-CH₂-O-CH₂-CH₃
• Methyl Ether: CH₃-O-CH₃ (Gas)

Methanol and Ethanol Industrial Uses

• Methanol: Highly toxic; ingestion attacks the optic nerve. Used as a solvent for fats, varnishes, lacquers, antifreeze, and raw material for methanal.
• Ethyl Alcohol: Colorless liquid (boiling point 78.3°C). Used in beverages, chemicals, perfumes, dyes, explosives, fuel, and as an antiseptic.

Alkyl Halides and Amines

Alkyl halides are hydrocarbons where hydrogen is substituted by a halogen.

• Physical Properties: Higher boiling points than corresponding alkanes; poorly soluble in water but soluble in alcohol and ether.