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O(g) + 2e^(-) to O^(2-)(g) , DeltaH(eg) ...

`O(g) + 2e^(-) to O^(2-)(g) , DeltaH_(eg) = 744.7` kJ/mole . The positive value of `DeltaH_(eg)` is due to :

A

energy is released to add on `1e^(-) " to " O^(-)`

B

energy is required to add on `1e^(-) " to " O^(-)`

C

energy is needed to add on `1e^(-) " to " O`

D

None of the above is correct

Text Solution

Verified by Experts

The correct Answer is:
B
Energy is always required to add second electron because of decrease of zeff after adding one electron.
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