Compounds of Silicon

Silicones are organo – silicon polymers containing Si – O – Si linkages. These are formed by the hydrolysis of alkyl or aryl substituted chlorosilanes and their subsequent polymerisation.

R3SiCl R3SiOH

Silanol
—> Silicone

R2SiCl2 gives rise to straight chain linear polymers

RSiCl3 gives a complex cross linked polomer



These polymers are used in water proofing textiles in glassware, as lubricants and anti foaming agents.

Silicon Carbide (Carborundum), SiC

It is obtained when a mixture of sand, carbon common salt and saw dust is strongly heated in an electric furnace

SiO2 + 3C —> SiC + 2CO

It is chemically inert and resists the attack of almost all the reagents. It is used as an abrasive to make grind stones knife sharpness, etc.

Illustration : What is etching of glass ? How does to happens?

Solution: Glass is chemically attacked by HF

This is known as etching of glass due to corrosive action of HF

Na2SiO3 + 6HF —> 2NaF + SiF4 + 3H2O

CaSiO3 + 6HF —> CaF2 SiF4 + H2O

SiF4 + 2HF —> H2SiF6

Next Page→

←Back Page

Leave a Reply