This chapter focuses on the detailed reaction mechanisms of hydrocarbons, emphasizing how and why reactions occur at the molecular level. It is a fundamental topic in Class 11–12 organic chemistry, crucial for competitive exam aspirants and undergraduate learners, as it builds the base for understanding reactivity and advanced organic transformations.
In this section, you will study:
Reaction mechanisms of alkanes, alkenes, alkynes, and aromatic hydrocarbons
Free radical substitution reactions in alkanes
Electrophilic addition reactions of alkenes and alkynes
Regioselectivity and stereoselectivity (Markovnikov, anti-Markovnikov additions)
Mechanism of ozonolysis and oxidative cleavage
Aromatic hydrocarbons and electrophilic substitution mechanism
Energy profiles, intermediates, transition states, and reaction conditions
NCERT-aligned mechanisms, diagrams, MCQs, and exam-oriented questions
The content is structured to build mechanistic clarity, improve logical reasoning, and strengthen the ability to predict reaction outcomes under different conditions.
Mastering hydrocarbon reaction mechanisms enables students to confidently solve mechanism-based questions, understand reaction trends, and form a strong foundation for advanced organic chemistry topics.
Q. In the reaction of cyclohexene with H2 in the presence of a catalyst, what is the expected product?
A.
Cyclohexane
B.
Hexane
C.
Cyclohexanol
D.
1-hexene
Solution
The hydrogenation of cyclohexene in the presence of a catalyst leads to the formation of cyclohexane.
Q. Which mechanism is primarily involved in the reaction of alkenes with bromine?
A.
Electrophilic addition
B.
Nucleophilic substitution
C.
Radical substitution
D.
Elimination
Solution
The reaction of alkenes with bromine involves an electrophilic addition mechanism, where the alkene acts as a nucleophile and attacks the electrophilic bromine molecule.
