Sodium bicarbonate $(NaHCO_3)$ has:

Which of these is least likely to act as a Lewis base?

What is the limitation of the framework model?

Which of the following is not a Lewis base?

Which of the following pairs are isoelectronic and isostructural?
$NO_3^{-}, CO_3^{2-}, ClO_3^{-}, SO_3, NO_2^{-}$

$A$ tin chloride $Q$ undergoes the following reactions (not balanced):
$Q + Cl^{-} \rightarrow X$
$Q + Me_3N \rightarrow Y$
$Q + CuCl_2 \rightarrow Z + CuCl$
$X$ is a monoanion having pyramidal geometry. Both $Y$ and $Z$ are neutral compounds. Choose the correct option$(s)$.
$(1)$ The central atom in $X$ is $sp^3$ hybridized
$(2)$ The oxidation state of the central atom in $Z$ is $+4$
$(3)$ The central atom in $Z$ has no lone pair of electrons
$(4)$ There is a coordinate bond in $Y$