Question

The general formula of double chain silicates is:

• A. $Si{O}_4^{4-}$
• B. $S{i}_3{O}_9^{2-}$
• C. $S{i}_2{O}_7^{6-}$
• D. $(S{i}_4{O}_{11}{)}_n^{6n-}$

Answer 1

The correct option is D $(S{i}_4{O}_{11}{)}_n^{6n-}$

The general formula of double-chain silicates is $(S{i}_4{O}_{11}{)}_n^{6n-}$. Two simple chains are joined together by shared oxygen. Also known as amphiboles.

E.g.

1) Asbestos - These are noncombustible fibrous silicates. They have been used for thermal insulation material, brake linings, construction material, and filters. These are carcinogenic amphiboles affecting the lungs. Hence their applications are restricted nowadays.

2) Tremolite - $C{a}_{2}M{g}_5{\left(S{i}_4{O}_{11}\right)}_2{\left(OH\right)}_2$

Note: The single and double chain silicates are collectively known as Inosilicates.

Hence the correct option is d.