$(A) + Cl_2 \xrightarrow{hv} \text{monochloro product}$. To maximize the yield of the monochloro product in the above reaction:

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 + $Br_2/hv$

Write the reactions for the preparation of ethane from the following:
$(i)$ Acetic acid $(CH_3COOH)$
$(ii)$ Methane $(CH_4)$
$(iii)$ Acetate ion $(CH_3COO^{-})$

In the reaction,$2n \ R-X \xrightarrow[\text{Dry ether}]{+2n \ Na} \text{product}$. The product obtained is

$A$ gaseous alkane undergoes complete combustion with oxygen. The ratio of the volume of $O_2$ required to the volume of $CO_2$ formed is $7 : 4$. The molecular formula of the alkane is:

Which of the following hydrocarbons will be in a liquid state at room temperature?