NEET2007Chemistryp Block Elements (Group 13 & 14)Actual
Which of the following anions is present in the chain structure of silicates?
Options
- A( Si ₂ O ₅²⁻ )_n
- B( SiO ₃²⁻ )_n
- CSiO ₄⁴⁻
- DSi ₂ O ₇⁶⁻
Correct answer
B. ( SiO ₃²⁻ )_n
Step-by-step solution
In silicates, two oxygen atoms per SiO ₄ tetrahedron are shared giving polymeric anion chains. When each tetetrahedron ( ( SiO ₄⁴⁻ ) ) shares two O atoms, infinite chains are formed. The formula of these extended anions approximates to ( ( SiO ₃ )_n^ 2 n- ) or ( ( SiO ₃²⁻ )_n . SiO ₄⁴⁻ ) anion is present in orthosilicates. ( Si ₂ O ₇⁶⁻ ) anion is present in pyrosilicates, while ( ( Si ₂ O ₅²⁻ )_n ) anion is present in double-chain silicates as well as in sheet silicates. Structure of silicate: