Silicon tetrachloride, Silicates, Zeolites, Silicones

Silicates :
Silicon and oxygen compounds are called silicates they have SiO_4^{-4} units.

Types :

• Ortho silicates
• pyro silicates
• cyclic silicates
• chain silicates
• sheet
• frame work silicates

Ortho silicates :
SiO_4^{-4} units
ex : ZrSiO₄ (Zircone)

Pyro silicates :
One oxygen of SiO_4^{-4} unit is shared with another unit.
It contains Si_{2}O_7^{-6} units.

Cyclic silicates :
It has 2 shared oxygen atoms.
It contains \left(SiO_3\right)_n^{-2n}
ex : Beryl – Be₃Al₂(SiO₃)₆

Chain silicates :
Single chain (Pyroxene)
It contains\left(SiO_3\right)_n^{-2n}two oxygens of \left(SiO_4\right)^{-2} units are shared with another units contain \left(SiO_3\right)_{n}^{-2n} units.

Sheet silicates :
3 oxygens of SiO_4^{-4} units are shared with other units.
Contains \left(Si_{2}O_5\right)_{n}^{-2n}units.
ex : Kaolin → Al₂(OH)₄Si₂O₅
Frame work silicates :
4 oxygens of SiO_4^{-4} units are shared with other units.
It contains SiO₂ units
ex : Quartz - SiO₂
       Zeolite - ZnO
Zeolites :
They are 3d - silicates.
they have honeycomb like structure (or) cage like structure.
They trap the molecules like H₂O, CO₂, NH₃ -------