In a complex reaction, the products are formed through a sequence of elementary reactions. This sequence of elementary reactions is called the:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → mechanism of the reaction
A reaction that takes place in one step is an elementary reaction. Most reactions go through several such steps; the series of elementary steps by which the reactants change into the products is the mechanism, and such reactions are called complex reactions.
NCERT (2026-27 edition):
3.2.3 Order of a Reaction – “The reactions taking place in one step are called elementary reactions. When a sequence of elementary reactions (called mechanism) gives us the products, the reactions are called complex reactions.”