An alkane (molecular weight $72$) forms only one monochlorinated product. Its formula is

Which of the following is $NOT$ obtained when a mixture of bromoethane and $1$-bromopropane is treated with sodium metal in dry ether?

When a certain alkane is mixed with chlorine and irradiated with ultraviolet light,only one monochloroalkane is formed. This alkane is likely to be:

Product $B$ is

The alkane from below having two secondary hydrogens is:

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 + $Br_2/hv$