Question

Among the following substituted silanes, the one which will give rise to cross-linked silicone polymer on hydrolysis is:
\[
  {\text{A}}{\text{.}}{{\text{R}}_{\text{2}}}{\text{SiC}}{{\text{l}}_{\text{2}}} \\
  {\text{B}}{\text{.}}{{\text{R}}_{\text{3}}}{\text{SiCl}} \\
  {\text{C}}{\text{.}}{{\text{R}}_4}{\text{Si}} \\
  {\text{D}}{\text{.RSiCl3}} \\
 \]

Answer 1

Hint: Silicon (Si) is the element of the periodic table which belongs to the carbon family. Atomic number of silicon is 14 and its atomic mass is 28.0855. It has its use in our daily life also. Silicone polymer is colourless, oil and rubber like substance which is made by material siloxane \[\left( {{\text{ }} - {R_2}Si - OSi{R_2}} \right)\].
HYDROLYSIS (hydro-water, lysis-breakdown):- Hydrolysis is organic chemical reaction and process in which breakdown of chemical bond takes place using a catalyst by nucleophilic substitution reaction.

Complete step by step answer:
Silicone is organo-silicone polymer:
When \[RSiC{l_3}\](Triclorosilicane) is reacted with water in the presence of hydrogen chloride then it changes into \[RSiO{H_3}\].
Chemical reaction occur as follows:
On reaction with water molecule, 
\[RSiC{l_3}\]​ gives \[RSi{\left( {OH} \right)_3}\]  which polymerizes to cross-linked silicone polymer.
Then hydrolysis of methyl methoxy hydroxy silicone occurs by the condensation with water dimer and is found in the intermediate reaction. \[RSiO{H_3}\]under polymerisation reaction gives the cross linked silicone polymer by removal of four molecules of water.
According to this hydrolysis reaction which gives the cross linked silicone polymer \[{\text{RSiC}}{{\text{l}}_{{\text{3}}}}{\text{ + }}{{\text{H}}_{\text{2}}}{\text{O + 3HCl}} \to {\text{RSi}}{\left( {{\text{OH}}} \right)_3}_\xrightarrow{{{\text{polymerisation}}}}{\text{cross - linked silicone polymer}}{\text{.}}\]

Thus option D, i.e. \[RSiC{l_3}\] is correct since it is the only silane compound which forms this kind of cross linkage in its structures, other substances form the hydroxide and acid on reacting with water molecules, they do not give rise to cross linkages.

So, the correct answer is Option D.

Note: Tricloro Silanes is a basic ingredient used in production of purified cross linked silicone polymer. It’s decomposed to produce silicone polymer in the presence of water and hydrochloric acid. And this kind of reaction is not done by \[{R_4}Si,{\text{ }}{R_2}SiC{l_2}{\text{ }}and{\text{ }}{R_3}SiCl.\] The application of these substances is in the manufacturing industry for producing semiconductor devices, solar panels and transistors.