Classification Of Elements And Periodicity In Properties Ques 243
Question: The formation of the oxide ion $ O_{(g)}^{2-} $ requires first an exothermic and then an endothermic step as shown below $ {O_{(g)}}+{{e}^{-}}=O_{(g)}^{-}\Delta H^{0}=-142\ kJmo{{l}^{-1}} $ $ O_{(g)}^{-}+{{e}^{-}}=O_{(g)}^{2-}\Delta H^{0}=844\ kJmo{{l}^{-1}} $ This is because [AIEEE 2004]
Options:
A) $ {{O}^{-}} $ ion will tend to resist the addition of another electron
B) Oxygen has high electron affinity
C) Oxygen is more electronegative
D) $ {{O}^{-}} $ ion has comparatively larger size than oxygen atom
Show Answer
Answer:
Correct Answer: A
Solution:
The addition of second electron in an atom or ion is always endothermic.
