question_answer 54)

  Silicon has strong tendency to form polymers like silicones. The chain length of silicone polymer can be controlled by adding: (a)\[MeSiC{{l}_{3}}\]                      (b) \[M{{e}_{2}}SiC{{l}_{2}}\]                      (c) \[M{{e}_{3}}SiCl\]                     (d)\[M{{e}_{4}}Si\]

Answer:

  (c) \[M{{e}_{3}}SiCl\]on hydrolysis gives a product which consists only one OH group which can form only dimer. Thus, the chain length of the silicone polymer can be controlled by adding\[M{{e}_{3}}SiCl\]. \[M{{e}_{3}}SiCl+{{H}_{2}}O\xrightarrow{{}}M{{e}_{3}}SiOH+HCl\] \[M{{e}_{3}}SiCl+HOSiM{{e}_{3}}\xrightarrow{{}}M{{e}_{3}}Si-O-SiM{{e}_{3}}\]