Explanation: The basicity of a compound depends on the availability of the lone pair of electrons on nitrogen for protonation. The order of basic strength is:
N(sp3, localized lone pair) > N(sp2, localized lone pair) > N(sp2, delocalized lone pair, aromatic).
Thus, the order of basic strength is:
Piperidine > Pyridine > Pyrrole.
Thus the correct answer is Option 1.
Draw the possible isomers of:
\[ [ \text{Co}(\text{en})_2\text{Cl}_2 ]^+ \]
Let \( S = \left\{ m \in \mathbb{Z} : A^m + A^m = 3I - A^{-6} \right\} \), where
\[ A = \begin{bmatrix} 2 & -1 \\ 1 & 0 \end{bmatrix} \]Then \( n(S) \) is equal to ______.