What is obtained when chlorine is passed into boiling toluene and the product is hydrolysed?

Identify the product obtained when $2$-chlorobutane is heated with an aqueous solution of potassium hydroxide.

$A$ dihalogen derivative '$X$' of a hydrocarbon with three carbon atoms reacts with alcoholic $KOH$ to give another hydrocarbon which forms a red precipitate with ammoniacal $Cu_2Cl_2$. '$X$' gives an aldehyde upon reaction with aqueous $KOH$. What is the compound '$X$'?

Which of the following compounds will not produce a precipitate on reaction with $AgNO_3$?

Elimination of bromine from $2-$bromobutane results in the formation of

Which of the following species is most reactive in $S_{N}2$ reaction?