Chemical Thermodynamics · JEE Main previous year questions

2004 1 question

1. Q1562004 · 24 Apr 2004 · Shift 1

   The formation of the oxide ion ${\mathrm{O}}^{2-}(\mathrm{g})$ requires first an exothermic and then an endothermic step as shown below ${\mathrm{O}}_{(\mathrm{g})}+{\mathrm{e}}^{-}={\mathrm{O}}_{(\mathrm{g})}^{-}$ $\Delta H^{\circ }=-142\mathrm{kJmo}{\mathrm{l}}^{-1}$ ${\mathrm{O}}_{(\mathrm{g})}^{-}+{\mathrm{e}}^{-}={\mathrm{O}}_{(\mathrm{g})}^{2-}$ $\Delta H^{\circ }=844\mathrm{kJmo}{\mathrm{l}}^{-1}$ This is because

   1. A.${\mathrm{O}}^{-}$ ion will tend to resist the addition of another electron
   2. B.Oxygen has high electron affinity
   3. C.Oxygen is more electronegative
   4. D.${\mathrm{O}}^{-}$ ion has comparatively larger size than oxygen atom
   Show answer

   Answer: A