Identify the total number of carbon atoms present in undecane.

Consider the given sequence of reactions.
$C_2H_6 + \frac{3}{2}O_2$ $\xrightarrow[\Delta]{(CH_3COO)_2Mn} X$ $\xrightarrow{NaOH} Y$
Electrolysis of aqueous solution of $Y$ gives gases $P$ and $Q$ at anode. $P$ and $Q$ are respectively.

Compound $(P)$ is

Identify the major product $(99 \%)$ formed when $(CH_3)_3CH$ is treated with $Br_2$ in $UV$ light.

$A$ 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.

Which of the following isomeric heptanes can yield seven different monochlorinated products upon free radical chlorination?