GENERAL ORGANIC CHEMISTRY (GOC)
Handwritten-notes inspired • NEET / JEE Main / JEE Advanced
1. Introduction & Why GOC Matters
General Organic Chemistry (GOC) provides the basic concepts needed to understand organic reactions
and their mechanisms.
• Explains how organic reactions occur.
• Helps predict the stability of reaction intermediates.
• Helps understand reaction rates and product formation.
• Electronic effects help compare acidity, basicity and stability.
Topics listed in the lecture
Inductive effect • Resonance / mesomeric effect • Hyperconjugation • Aromaticity • Stability of
intermediates • Acidic/basic strength • Resonance energy • Heat of combustion • Heat of hydrogenation •
Electrophiles and nucleophiles • PYQs
2. Basic Concepts of a Reaction
Reactant + Reagent → Product
• Reactant / substrate: species that participates in the reaction; the reagent acts on the substrate.
• Reagent: species that reacts with the substrate to bring about a chemical transformation.
• Intermediate: species formed during a reaction mechanism and consumed in a later step.
• Transition state: high-energy configuration where bonds may be partly broken and partly formed.
Reaction changes: old bonds break, new bonds form; the desired organic product is the main focus, and
by-products may also form.
Two reaction pathways
Through an intermediate: Reactant → Intermediate → Product. One or more intermediates form.
Through a transition state: Reactant → Transition state → Product. Bond breaking and bond formation
can occur in one concerted step; SN2 is a key example.
Remember: A transition state is not an isolable intermediate.
GOC • Exam-focused revision notes Page 1
, 3. Bond Cleavage (Bond Breaking)
A. Heterolytic cleavage
Definition: both bonding electrons go to one of the bonded atoms.
A—B → A■ + B■ or A—B → A■ + B■
• Unequal distribution of bonding electrons.
• Produces oppositely charged species (ions).
• If carbon receives a positive charge, a carbocation may form; if carbon receives the pair, a carbanion
may form.
Example: CH■—Br → CH■■ + Br■ (bromine receives both bonding electrons).
B. Homolytic cleavage
Definition: each bonded atom receives one electron from the shared pair.
A—B → A• + B•
• Equal distribution of bonding electrons.
• Produces free radicals containing unpaired electrons.
• The dot (•) represents an unpaired electron.
Example: Cl■ —(hν)→ 2Cl•
Comparison
Feature Heterolytic Homolytic
Electron distribution Unequal Equal
Electrons received Both to one atom One each
Products Ions Free radicals
Notation A■ + B■ A• + B•
Memory trick: Heterolytic → ions; Homolytic → radicals.
GOC • Exam-focused revision notes Page 2
Handwritten-notes inspired • NEET / JEE Main / JEE Advanced
1. Introduction & Why GOC Matters
General Organic Chemistry (GOC) provides the basic concepts needed to understand organic reactions
and their mechanisms.
• Explains how organic reactions occur.
• Helps predict the stability of reaction intermediates.
• Helps understand reaction rates and product formation.
• Electronic effects help compare acidity, basicity and stability.
Topics listed in the lecture
Inductive effect • Resonance / mesomeric effect • Hyperconjugation • Aromaticity • Stability of
intermediates • Acidic/basic strength • Resonance energy • Heat of combustion • Heat of hydrogenation •
Electrophiles and nucleophiles • PYQs
2. Basic Concepts of a Reaction
Reactant + Reagent → Product
• Reactant / substrate: species that participates in the reaction; the reagent acts on the substrate.
• Reagent: species that reacts with the substrate to bring about a chemical transformation.
• Intermediate: species formed during a reaction mechanism and consumed in a later step.
• Transition state: high-energy configuration where bonds may be partly broken and partly formed.
Reaction changes: old bonds break, new bonds form; the desired organic product is the main focus, and
by-products may also form.
Two reaction pathways
Through an intermediate: Reactant → Intermediate → Product. One or more intermediates form.
Through a transition state: Reactant → Transition state → Product. Bond breaking and bond formation
can occur in one concerted step; SN2 is a key example.
Remember: A transition state is not an isolable intermediate.
GOC • Exam-focused revision notes Page 1
, 3. Bond Cleavage (Bond Breaking)
A. Heterolytic cleavage
Definition: both bonding electrons go to one of the bonded atoms.
A—B → A■ + B■ or A—B → A■ + B■
• Unequal distribution of bonding electrons.
• Produces oppositely charged species (ions).
• If carbon receives a positive charge, a carbocation may form; if carbon receives the pair, a carbanion
may form.
Example: CH■—Br → CH■■ + Br■ (bromine receives both bonding electrons).
B. Homolytic cleavage
Definition: each bonded atom receives one electron from the shared pair.
A—B → A• + B•
• Equal distribution of bonding electrons.
• Produces free radicals containing unpaired electrons.
• The dot (•) represents an unpaired electron.
Example: Cl■ —(hν)→ 2Cl•
Comparison
Feature Heterolytic Homolytic
Electron distribution Unequal Equal
Electrons received Both to one atom One each
Products Ions Free radicals
Notation A■ + B■ A• + B•
Memory trick: Heterolytic → ions; Homolytic → radicals.
GOC • Exam-focused revision notes Page 2
