Question

What do you mean by complex reaction?

Answer 1

The overall reaction occurs in order in which it is not equal to molecularity of reaction. Mechanisms of complex reaction can consist of a no. of electron step transfer.

Complete step by step answer:
The term 'complex reaction' generally refers to a reaction whose mechanism consists of more than 1 elementary step. Such a rate law which is experimentally determined may be compared with the predicted rate law for a given mechanism in an order to find whether the proposed mechanism is actually the correct one.
Complex reaction mechanisms can consist of a no. of electron transfer steps, with some of the chemical steps before or after the electron transfer steps or taking place in between them. Most organic electrochemical reactions are complicated, complex, involving large numbers of electrons in the whole reaction.
In simpler terms, when the whole reaction does not complete in one step, it means it occurs as a complex reaction or in many steps, in which order is not equal to molecularity of reaction.

Additional information: Complex reaction time or compound reaction time is the latency b/w a variable stimulus and a variable response respectively. Go/NoGo which is also known as Recognition reaction time task in which participants give attention to 1 certain event but ignore other events.
A reaction intermediate or an intermediate is a molecular entity which is created from the reactants (or preceding intermediates) and reacts further to give the directly noticed products of a chemical reaction. Most of the chemical reactions are step based, which means they take more than 1 elementary step to complete.

Note:
There are many reactions so don’t get confused, observe the hint carefully and complex reaction time is also known as compound reaction time.