Complete the reactions:
$1. CH_4 + O_2 \xrightarrow{Mn_2O_3, \Delta} ?$
$2. CH_3CH_3 + O_2 \xrightarrow{(CH_3COO)_2Mn, \Delta} ?$

Among the following free radical bromination reactions,select those in which a $2^o$ halide is the major product. The reactions are as follows:
$(P)$ Cyclohexane + $Br_2/hv$
$(Q)$ Methylcyclobutane + $Br_2/hv$
$(R)$ Ethylbenzene + $Br_2/hv$
$(S)$ $3-$Methylhexane + $Br_2/hv$
$(T)$ Decalin + $Br_2/hv$
$(U)$ Butane + $Br_2/hv$

Why are alkanes known as "Paraffins"?

Identify the total number of carbon atoms present in undecane.

In commercial gasolines,the type of hydrocarbons which are more desirable is

When the fuel mainly contains ...............,knocking occurs more in the engine.