Question

What is general formual of below mentioned silicate? [o : oxygen; ⚫ : silicon]

• A. $(Si_4O_{11}^{6-})_n$
• B. $(Si_2O_5^{2-})_n$
• C. $(Si_6O_{17}^{10-})_n$
• D. $(Si_3O_8^{4-})_n$

Answer 1

Answer: (A)

$(Si_4O_{11}^{6-})_n$

Answer 2

The given structure is a double chain silicate. The general formula of a double chain silicate, like amphibole, is $(Si_4O_{11}^{6-})_n$. Each silicon atom is tetrahedrally coordinated with oxygen atoms. The repeating unit consists of linked tetrahedra forming a chain-like structure. By counting the silicon and oxygen atoms in the repeating unit, and considering the charge balance, the general formula can be determined.