Among the following substituted silanes the one which will give rise to cross linked silicone polymer on hydrolysis is

When an organochlorosilane $$R_nSiCl_{4-n}$$ is hydrolysed, each $$Si{-}Cl$$ bond reacts with water to form a $$Si{-}OH$$ group:

$$R_nSiCl_{4-n} + (4-n)H_2O \rightarrow R_nSi(OH)_{4-n} + (4-n)HCl$$

Subsequent condensation of the $$Si{-}OH$$ groups gives $$Si{-}O{-}Si$$ linkages, building a silicone polymer.

• If a silicon atom carries three or four hydrolysable groups, each Si centre can connect with three or four neighbours, producing a three-dimensional, cross-linked network.
• If it carries only two hydrolysable groups, the condensation can proceed in just two directions, giving a linear chain.
• With only one hydrolysable group, the molecule merely caps a growing chain and acts as a chain-terminator.

Now analyse the given molecules:

Option A $$R_4Si$$
No $$Si{-}Cl$$ bonds are present, so no hydrolysis or polymerisation occurs. No polymer formed.

Option B $$RSiCl_3$$
Here, $$n=1$$ and $$(4-n)=3$$. Each silicon bears three hydrolysable $$Cl$$ groups. After hydrolysis it becomes $$RSi(OH)_3$$, and each Si atom can bond to three others, giving a cross-linked (three-dimensional) silicone network.

Option C $$R_2SiCl_2$$
The silicon carries only two $$Cl$$ groups. Hydrolysis yields $$R_2Si(OH)_2$$ which condenses to form a linear silicone chain, not a cross-linked polymer.

Option D $$R_3SiCl$$
Only one $$Cl$$ group is present. After hydrolysis the molecule becomes $$R_3SiOH$$ and can attach at just one end; it terminates polymer chains rather than forming them.

Thus, the only compound capable of generating a three-dimensional cross-linked silicone polymer on hydrolysis is $$RSiCl_3$$.

Option B which is: $$RSiCl_3$$