Chemistry Chapter 8 Organic Chemistry Class 11 Notes FREE PDF

Introduction to Organic Chemistry

  • Coined by Berzelius in 1807.

  • Initially based on vitalism theory, suggesting living systems had a unique 'vital force'.

Discovery by Friedrich Wohler

  • Synthesized an organic compound from an inorganic one in 1828, debunking vitalism.

  • Highlights carbon's unique catenation property allowing diverse compounds.

General Organic Chemistry

  • Study of foundational concepts in chemical reactions.

  • Reaction mechanisms describe bond formation and breaking:

    • Sigma Bond: Stronger, overlaps along inter-nuclear axis.

    • Pi Bond: Weaker, overlaps perpendicularly to inter-nuclear axis.

Structural Formulas

  • Lewis Structures: Represent all bonding electron pairs.

  • Condensed Formulas: Simplified representations with central atoms.

Line-Angle Formulas

  • Skeletal structures showing bonds; carbon implied at intersections.

  • 3-D representations use solid and dashed wedges for bond orientations.

Hybridization

  • Mixing of atomic orbitals resulting in hybrid orbitals:

    • Size Order: sp3 > sp2 > sp.

    • Electronegativity Order: sp > sp2 > sp3.

Dienes

  • Types of dienes:

    • Isolated: Double bonds separated by at least one sp3 carbon.

Stability of Dienes

  • Stability order: Isolated > Conjugated > Cumulated.

Forms of Carbon

  • Common forms include Diamond, Graphite, Carbides, Fullerenes, and Charcoal.

Fission Types

  • Homolytic Fission: Each atom retains one electron, forming free radicals.

  • Heterolytic Fission: Shared electron pair moves creating cations and anions.

Inductive Effect

  • Inequal electron sharing in bonds leads to inductive effects influenced by electronegativity differences.

Electron Donating and Withdrawing Groups

  • EDG: +I effect, increases electron density.

  • EWG: -I effect, decreases electron density.

Basicity of Amines

  • Basic strength order in gas/liquid: 3° > 2° > 1° > NH3.

Concept of Resonance

  • Some molecules require multiple Lewis structures to describe resonance.

Validity of Lewis Structures

  • Rules include octet fulfillment, maintaining atomic positions, and coplanarity.

Mesomeric Effect

  • Permanent polarization in conjugated systems indicating stability.