The formation of the oxide ion {\O}^{2-}( {\g}) requires first an exothermic and then an endothermic step as shown below {\O}_{( {\g})}+ {\e}^{-}=O_{(g)}^{-} ∆ {\H}^{∘}=-142 {\kJmol}^{-1} O_{(g)}^{-}+ {\e}^{-}=O_{(g)}^{2-} ∆ {\H}^{∘}=844 {\kJmol}^{-1} This because

Question

The formation of the oxide ion  {\O}^{2-}( {\g}) requires first an exothermic and then an endothermic step as shown below  {\O}_{( {\g})}+ {\e}^{-}=O_{(g)}^{-} ∆  {\H}^{∘}=-142  {\kJmol}^{-1}  O_{(g)}^{-}+ {\e}^{-}=O_{(g)}^{2-} ∆  {\H}^{∘}=844  {\kJmol}^{-1} This because

Examsnet · Accepted Answer

Correct Answer is : O−ion will tend to resist the addition of another electron

AIEEE 2004 Chemistry Solved Paper