Methane can be prepared by

What is the bond length of the $C-C$ bond in an alkane where all carbon atoms are $sp^{3}$ hybridized (in $pm$)?

As the number of carbon atoms in an alkane chain increases,the boiling point...........

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 + $Br_2/hv$

What is the product of the following reaction?
$p-CH_3C_6H_4MgBr + CH_3CH_2OH \rightarrow ?$

In the following reaction,$A$ is: