(i) Silicon are the group of organosilicon polymers having (R2SiO) repeating unit. For manufacturing silicone, starting material is alkyl or aryl substituted silicon chloride.
Methyl chloride react with silicon in the presence of copper powder as a catalyst at 573K, many types of methyl chlorosilanes like MeSiCl3, Me2SiCl2, Me3SiCl with small amount of Me4Si are formed. Further addition of water form the straight-chain polymer.
They are used as greases, sealant, for waterproofing fabric, electrical insulators.
Also used as a surgical and cosmetic plant.
(ii) Borane is a simple form of boron hydride. It is prepared by treating lithium aluminium hydride with trifluoride in diethyl ether.
4BF3 + 3 LiAlH4 → 2B2H6 + 3LIF + 3AlF3
It is also prepared by oxidation of sodium borohydride with iodine. For example:
2NaBH4 + I2 → B2H6 + 2NaI + H2
Diborane is also produced on an industrial scale by reacting with BF3 with NaH
2BF3 + 6NaH → B2H6 + 6NaF
Diborane is colourless gas and is highly toxic. It has boiling point 180K.
Rate this question :