Q.Identify to which type does the following complex reactions belongs to :

Complex reactions are classified as opposing, side (parallel) or consecutive reactions based on how their elementary steps are related; each of the three examples given illustrates one distinct type.

1. Dehydration of 2-methyl-2-butanol — Side (parallel) reaction Acid/alumina-catalysed E1 dehydration of 2-methyl-2-butanol can lose a proton from either of two different β-carbons, so two alkenes are formed simultaneously from the same carbocation intermediate: $CH_3CH_2C(CH_3)_2OH \xrightarrow{-H_2O} \big[(CH_3)_2\overset{+}{C}-CH_2CH_3\big] \rightarrow \text{2-methyl-2-butene (major)} + \text{3-methyl-1-butene (minor)}$ When a single reactant gives two (or more) different products by parallel paths with different rate constants ($k_1$, $k_2$, …), it is called a side reaction / parallel reaction.
2. Isomerisation of cyclopropane — Opposing (reversible) reaction $\text{Cyclopropane} \underset{k_{-1}}{\overset{k_1}{\rightleftharpoons}} \text{Propene}$ The forward isomerisation (ring opening to propene) and the reverse reaction both occur, and the system approaches an equilibrium concentration ratio rather than going to 100% completion — the hallmark of an opposing (reversible) first-order reaction, treated kinetically with both $k_1$ and $k_{-1}$.
3. Saponification of a diester — Consecutive (sequential) reaction …