Question
For a compound LiAl(SiO3)2, what is the charge on SiO3 unit? What is the arrangement of oxygen atoms around the silicon atom?
Solution
The charge on SiO3 on LiAl(SiO3)2 is –2 i.e., it exists as (SiO3)2– ion. The structure of (SiO3)2– ion is as shown.
In the compound
, the silicon is sp3 hybridised and the four oxygen atoms are arranged tetrahedrally around it. Also, two of the oxygen atoms of each 
unit share with each Other giving simple chain structure as shown. Thus two of the oxgyen atoms from bridges while the remaining two carry one negative charge each.
In the compound
, the silicon is sp3 hybridised and the four oxygen atoms are arranged tetrahedrally around it. Also, two of the oxygen atoms of each unit share with each Other giving simple chain structure as shown. Thus two of the oxgyen atoms from bridges while the remaining two carry one negative charge each.
