The $4^{th}$ higher homologue of ethane is

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

The angle strain in cyclopropane is:

In the bromination of isobutane,the relative reactivity rates of $1^oH, 2^oH,$ and $3^oH$ are $1 : 82 : 1600$ respectively. Calculate the percentage yield of products $(a)$ and $(b)$ in the following reaction:
$CH_3-CH(CH_3)-CH_3 (excess) + Br_2 \xrightarrow{hv} (a) CH_3-C(Br)(CH_3)-CH_3 + (b) CH_3-CH(CH_3)-CH_2Br$

Identify the final product $C$ in the following reaction sequence:
$Br-(CH_2)_5-Br$ $\xrightarrow{Na, \text{D.E.}} A$ $\xrightarrow{Br_2, \Delta} B$ $\xrightarrow{\text{alc. KOH}, \Delta} C$

How is the iodination of alkanes performed?