MCQ
The formation of the oxide ion $O_{(g)}^{2 - }$ requires first an exothermic and then an endothermic step as shown below This is because
${{O}_{(g)}}+{{e}^{-}}=O_{(g)}^{-}\Delta {{H}^{o}}=-142\ kJ\,mo{{l}^{-1}}$
$O_{(g)}^{-}+{{e}^{-}}=O_{(g)}^{2-}\Delta {{H}^{o}}=844\ kJ\,mo{{l}^{-1}}$
- ✓${O^ - }$ ion will tend to resist the addition of another electron
- BOxygen has high electron affinity
- COxygen is more electronegative
- D${O^ - }$ion has comparatively larger size than oxygen atom
