If the octane number of a sample of petrol is $40$,it is a mixture of........and............

Which of the following compounds is the most stable?

What is formed when isobutylmagnesium bromide reacts with absolute alcohol?

$A$ sample of $2,3-$dibromo$-3-$methylpentane is heated with zinc dust. The resulting product is isolated and then heated with $HI$ in the presence of red phosphorus. Indicate the structure that represents the final organic product formed in the reaction.

Identify the initiation step$(s)$ $(X)$ and termination step$(s)$ $(Y)$ of free radical chlorination of $CH_4$ from the following:
$a) \dot{C}H_3 + \dot{Cl} \rightarrow CH_3-Cl$
$b) \dot{Cl} + \dot{Cl} \rightarrow Cl_2$
$c) \dot{C}H_3 + Cl_2 \rightarrow CH_3-Cl + \dot{Cl}$
$d) Cl_2 \rightarrow 2\dot{Cl}$
$e) CH_4 + \dot{Cl} \rightarrow \dot{C}H_3 + HCl$
$f) \dot{C}H_3 + \dot{C}H_3 \rightarrow CH_3-CH_3$

Describe the Kolbe electrolysis reaction of $C_{2}H_{5}COO^{-}Na^{+}$ at the anode and cathode.