Answer to Question #84557 in Inorganic Chemistry for anuj kumar

Question

Write the structures of pyrosilicates and chain silicates.

Answer 1

Pyrosilicates

Pyrosilicates are formed when two SiO₄^4- tetrahedra share one corner. The sharing of one oxygen atom between two SiO₄^4– tetrahedra gives rise to Si₂O₇^6– anion. These anion can be represented as:

Examples of pyrosilicates are thortveitite,Sc₂(Si₂O₇) , hemimorphite, Zn₃(Si₂O₇)Zn(OH)₂*H₂O .

Chain silicates

When two corners of a tetrahedron are shared in such a manner that a linear single stranded chain is formed, then the silicates containing such chains are called chain silicates. The single chain silicates have the general formula (SiO₃^2-)_n or (SiO₃)_n^2n- . The anions in chain silicates can be represented as:

When two corners of a tetrahedron are shared in such a manner that a linear single stranded chain is formed, then the silicates containing such chains are called chain silicates. The single chain silicates have the general formula (SiO₃^2-)_n or (SiO₃)_n^2n- . The anions in chain silicates can be represented as:

The chain silicates having single strands are found in minerals called pyroxenes. Examples of pyroxenes are spodumene, LiAl(SiO₃)₂ and diopside, CaMg(SiO₃)₂.

Chain silicates can also have double strands. Such double chains are formed when two single chains are linked by sharing of oxygen atoms. They have the general formula (Si₄O₁₁^6-)_n or (Si₄O₁₁)_n^6n- .

Chain silicates can also have double strands. Such double chains are formed when two single chains are linked by sharing of oxygen atoms. They have the general formula (Si₄O₁₁^6-)_n or (Si₄O₁₁)_n^6n- .

These double chain structures are present in asbestos. The double chain silicates are also known as amphiboles.