Identify the polymer system under hydrolytic conditions

Hydrolysis of organochlorosilanes gives silicones.

For example, $R_2SiCl_2 + 2H_2O \rightarrow R_2Si(OH)_2 + 2HCl$

Then condensation occurs: $n\,R_2Si(OH)_2 \rightarrow [-R_2Si-O-]_n + nH_2O$

This gives a linear silicone polymer.

Compound used for preparation of linear polymer

To get a linear polymer, the monomer must be difunctional, so that it can form two bonds in the chain.

Among the given compounds:

• $CH_3SiCl_3$ is trifunctional $\Rightarrow$ gives cross-linked/network polymer.
• $(CH_3)_2SiCl_2$ is difunctional $\Rightarrow$ gives linear polymer.
• $SiCl_4$ is tetrafunctional $\Rightarrow$ highly cross-linked structure.

Therefore, the compound for preparation of a linear polymer is: $(CH_3)_2SiCl_2$

Compound used for chain termination

A chain terminator should be monofunctional, so it can cap the growing chain ends without further propagation.

Among the options:

• $(CH_3)_3SiCl$ is monofunctional.

On hydrolysis: $(CH_3)_3SiCl + H_2O \rightarrow (CH_3)_3SiOH + HCl$

This caps the polymer end as a terminal group like $-(Si(CH_3)_3)$ and stops further chain growth.

Hence, the chain-terminating compound is: $(CH_3)_3SiCl$

Check each option

• A: $CH_3SiCl_3$ and $Si(CH_3)_4$

  • First compound gives cross-linked polymer, not linear.
  • $Si(CH_3)_4$ is not the usual hydrolysable chain terminator.
  • Incorrect.

• B: $(CH_3)_2SiCl_2$ and $(CH_3)_3SiCl$

  • First gives linear silicone polymer.
  • Second acts as chain terminator.
  • Correct.

• C: $(CH_3)_2SiCl_2$ and $CH_3SiCl_3$

  • Second is trifunctional, causes branching/cross-linking, not termination.
  • Incorrect.

• D: $SiCl_4$ and $(CH_3)_3SiCl$

  • $SiCl_4$ gives network polymer, not linear.
  • Incorrect.

Final answer

The correct pair is: $\boxed{(CH_3)_2SiCl_2 \text{ and } (CH_3)_3SiCl}$

So, Option B is correct.