Question

Halogens have ------ electron affinity

a. exothermic
b. endothermic
c . positive
d . zero

Answer 1

a

Answer 2

There are 2 approaches to this. The first is to look at E˚ values for the halogens. The second would be to say that halogens form halides to attain the octet structure. Hence electron affinity is exothermic.
\[E^0 = -\frac{∆G}{zF} = \frac{T∆S - ∆H}{zF}\]