Calculate the emf of the following cell:

$$\mathrm{Ni}(\mathrm{~s})+2 \mathrm{Ag}^{+}(0.01 \mathrm{M}) \rightarrow \mathrm{Ni}^{2+}(0.1 \mathrm{M})+2 \mathrm{Ag}(\mathrm{~s})$$

Given that $\mathrm{E}_{\text {cell }}^{\circ}=1.05 \mathrm{~V}, \log 10=1$

Account for the following:

(a) Haloalkanes react with AgCN to form isocyanide as main product.

(b) Allyl chloride shows high reactivity towards $\mathrm{S}_{\mathrm{N}} 1$ reaction.

(c) Haloarenes are extremely less reactive towards nucleophilic substitution reactions.

The rate constant of a reaction quadruples when the temperature changes from 300 K to 320 K . Calculate the activation energy for this reaction. $\left[\log 2=0.30, \log 4=0.60,2.303 \mathrm{R}=19.15 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right]$

A compound ' X ' with molecular formula $\mathrm{C}_3 \mathrm{H}_9 \mathrm{~N}$ reacts with $\mathrm{C}_6 \mathrm{H}_5 \mathrm{SO}_2 \mathrm{Cl}$ to give a solid, insoluble in alkali. Identify ' X ' and give the IUPAC name of the product. Write the reaction involved.