Basics of Organic Chemistry

 🧪 Basics of Organic Chemistry

Organic chemistry is the branch of chemistry that deals with the study of carbon compounds (except CO, CO₂, carbonates, etc.). It focuses mainly on hydrocarbons and their derivatives.

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🌟 1. Why Carbon is Special?

Tetravalent: Carbon has 4 valence electrons → forms 4 covalent bonds.

Catenation: Carbon can form long chains or rings with other carbon atoms.

Versatile Bonding: Can form single (C–C), double (C=C), or triple (C≡C) bonds.

📝 Example:

CH₄ → Methane (single bonds)

C₂H₄ → Ethene (double bond)

C₂H₂ → Ethyne (triple bond)

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🔥 2. Types of Hydrocarbons

Type Bond Type General Formula Example

Alkanes Single (C–C) CₙH₂ₙ₊₂ CH₄ (methane)

Alkenes Double (C=C) CₙH₂ₙ C₂H₄ (ethene)

Alkynes Triple (C≡C) CₙH₂ₙ₋₂ C₂H₂ (ethyne)

Aromatic Benzene ring C₆H₆ etc. Benzene

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🧬 3. Functional Groups

These are atoms or groups of atoms responsible for the chemical properties of organic molecules.

Functional Group Formula Example Name Suffix

Alcohol –OH CH₃CH₂OH –ol

Aldehyde –CHO CH₃CHO –al

Ketone –CO– CH₃COCH₃ –one

Carboxylic Acid –COOH CH₃COOH –oic acid

Amine –NH₂ CH₃NH₂ –amine

Ester –COOR CH₃COOCH₃ –oate

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🧪 4. Isomerism

Isomers are compounds with the same molecular formula but different structures.

Structural Isomers: Different connectivity (e.g. butane vs isobutane)

Stereoisomers: Same connectivity but different spatial arrangement

Geometrical (cis-trans)

Optical (mirror image)

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🧪 5. IUPAC Naming Rules (Simplified)

1. Identify the longest carbon chain → base name

2. Number the chain from the end closest to the functional group

3. Name and number side groups (methyl, ethyl, etc.)

4. Use prefixes & suffixes

e.g., 2-methylbutane

e.g., butan-2-ol

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🔁 6. Common Reactions in Organic Chemistry

Reaction Type Description Example

Substitution One atom/group replaced by another CH₄ + Cl₂ → CH₃Cl + HCl

Addition Atoms added across double/triple bonds C₂H₄ + H₂ → C₂H₆

Elimination Atoms removed, forming multiple bonds CH₃CH₂OH → CH₂=CH₂ + H₂O

Oxidation Increase in oxygen or loss of H Alcohol → Acid

Reduction Addition of hydrogen Aldehyde → Alcohol

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📘 Bonus: Organic Chemistry in Daily Life

Alcohols → hand sanitizers, beverages

Esters → fruity smells, perfumes

Carboxylic acids → vinegar (acetic acid)

Polymers → plastics (polyethylene, PVC)

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