What is the number of moles of $sp^2$ hybridized carbon atoms present in $n$ moles of isopentane?

Which of the following gases has the highest heat of combustion?

If per $H$-atom selectivity for chlorination is $3^o : 2^o : 1^o = 5 : 3.8 : 1$,then identify the correct product ratio for the following reactions.

Hydrocarbon $(A)$ reacts with bromine by substitution to form an alkyl bromide,which by Wurtz reaction is converted to a gaseous hydrocarbon containing less than four carbon atoms. $(A)$ is

Complete the reactions:
$CH_3(CH_2)_4CH_3 \xrightarrow[anhydrous \ AlCl_3, HCl_{(g)}]{isomerization} ?$
$n-\text{hexane} \xrightarrow{aromatization} ?$

Photochemical chlorination of alkane is initiated by a process of