UPSC Civil Services (Mains), Chemistry optional · 2022 · Paper I
Q3(a). The least stable of OCN⁻, ONC⁻ and SCN⁻
Question
Identify the least stable ion of the following ions and justify your answer: OCN⁻, ONC⁻, SCN⁻.
Answer in brief
ONC⁻, the fulminate ion, is the least stable: every Lewis structure of it needs a positive charge on nitrogen and a negative charge on carbon.
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Coversformal chargefulminate ioncyanatethiocyanateresonance structuresLewis structure
All parts of Question 3
- 3(a) The least stable of OCN⁻, ONC⁻ and SCN⁻10 marks
- 3(b) Entropy changes when an ice cube melts in the sea at 0 °C10 marks
- 3(c) Speed distribution curves of argon and helium10 marks
- 3(d) Phase diagram of water; critical point and triple point10 marks
- 3(e) Forces on an ion moving through a strong-electrolyte solution10 marks