Identify the product ' $B$ ' in the following series of reactions.

Isopropylcyanide $\xrightarrow[H \mathrm{Cl}]{\mathrm{SnCl}_2} \mathrm{~A} \xrightarrow{\mathrm{H}_3 \mathrm{O}^{+}} \mathrm{B}+\mathrm{NH}_4 \mathrm{Cl}$

For the reaction $2 \mathrm{~N}_2 \mathrm{O}_{5(\mathrm{~g})} \longrightarrow 4 \mathrm{NO}_{2(\mathrm{~g})}+\mathrm{O}_{2(\mathrm{~g})}$ rate and rate constant are $1.02 \times 10^{-4} \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}$ and $3.4 \times 10^{-5} \mathrm{~s}^{-1}$. What is the conc. of $\mathrm{N}_2 \mathrm{O}_5$ ?

Which from following ligands is able to form linkage isomers?

Identify the bond order and magnetic nature of $\mathrm{Li}_2$ molecule respectively.