Question

An alkyl halide reacts with a group $\,14\,$ element $\,Y\,$ at $\,570K\,$ with $\,Cu\,$ as a catalyst and produces a dialkyl chloro compound $\,Z\,$. The compound $\,Z\,$ on hydrolysis gives another compound which is a strong water repellent and quite inert chemically. The dioxide of $\,Y\,$ is acidic in nature. The alkyl halide can also be obtained from methane after monosubstitution. Identify $\,Y\,$ and $\,Z\,$ .
A.$\,Y = Si\,$ and $\,\,Z = {(C{H_3})_2}SiC{l_2}\,$
B.$\,Y = Si\,$ and $\,Z = C{H_3}Cl\,$
C.$\,Y = C$ and $\,Z = SiC{l_4}\,$
D.$\,Y = Si\,$ and $\,Z = CC{l_4}\,$

Answer 1

Hint: A carbon-halogen bond is the functional group of alkyl halides, with fluorine, chlorine, bromine and iodine as typical halogens. Group $\,14\,$ elements are carbon family which are the second group elements in the $\,p\,$- block in the periodic table. The elements of this group are Carbon $\,(C)\,$ Silicon $\,(Si)\,$, Germanium $\,(Ge)\,$, Tin $\,(Sn)\,$, Lead $\,(Pb)\,$, Flerovium $\,(Fl)\,$.

Complete step by step answer:
As from the above hint, it is clear that the compound $\,Y\,$ can be anyone among the elements mentioned above. Let us first analyse the reaction mentioned in the question;
So, in this reaction, there is an alkyl halide and we must first figure out that;
Methyl chloride is provided by mono-substitution of methane which can be the alkyl halide here. Then, by looking into the reactions of this methyl chloride in the presence of $\,Cu\,$ at $\,570K\,$, we can figure out the compounds here. A mixture of mono, di and tri methyl chlorosilanes and tetramethylsilane is formed by heating silicon with methyl chloride at high temperatures in the presence of copper.
$\,C{H_3}Cl + Si\xrightarrow[{570K}]{{Cu\,powder}}C{H_3}SiC{l_3} + {(C{H_3})_2}SiC{l_2} + {(C{H_3})_3}SiCl + {(C{H_3})_4}Si\,$
So, from the above explanations it is clear that compound $\,Y\,$ is $\,Si\,$ $\,($ silicon $\,)\,$ and compound $\,Z\,$ is $\,\,{(C{H_3})_2}SiC{l_2}\,$$\,(\,$ dimethyldichlorosilane $\,)\,$.
Hence, option A is the correct answer.


Note:
Dimethyldichlorosilane is a tetrahedral and organosilicon compound. It is a colourless liquid at room temperature which reacts readily with water to form both linear and cyclic $\,Si - O\,$ chains. As the principal precursor to dimethyl silicone and polysilane compounds, dimethyldichlorosilane is a major product which is produced in an industrial scale.