UPSC Civil Services (Mains), Chemistry optional · 2024 · Paper I
Q2(c)(ii). Stoichiometric defects
Question
Explain stoichiometric defects with an example.
Answer in brief
Stoichiometric defects are point defects that leave the cation-to-anion ratio, and so the formula and electrical neutrality, unchanged; the two kinds are the Schottky defect (as in NaCl) and the Frenkel defect (as in AgCl).
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Coversstoichiometric defectsSchottky defectFrenkel defectpoint defectsionic conductivity
All parts of Question 2
- 2(a) Uncertainty principle; orthogonality of ψ₁ and ψ₂ in a box10 marks
- 2(b)(i) Bond order of O₂, O₂⁻, O₂²⁻ and O₂⁺10 marks
- 2(b)(ii) Molecular orbital diagram of CO10 marks
- 2(c)(i) Limiting radius ratio for coordination numbers 3 and 610 marks
- 2(c)(ii) Stoichiometric defects10 marks