When vegetation is burnt in the absence of oxygen,which of the following will be formed?

$A$ compound reacts with $Cl_2$ to give product $(B)$,and the reaction of product $(B)$ with $(Zn + \text{dilute } HCl)$ gives back the original substance $(A)$. Give the structures of $(A)$ and $(B)$.

Which one of the following compounds cannot be prepared by Wurtz reaction?

The halogen which is most reactive in the free radical halogenation of alkanes under sunlight is

What are the physical properties of alkanes?

Which of the following has an octane number of zero?