Question

Electron affinity is the measure of the attraction of an electron toward an isolated gaseous atom. When an electron is added to an isolated gaseous atom or ion energy is either released or absorbed; this energy change is known as electron affinity. Electron affinity is positive when energy is absorbed, and it is negative when energy is released.identify which of the following statements matches each reaction.Statments =Electron affinity is -349 kJ.Electron affinity is +349 kJ.Electron affinity is -142 kJ.Electron affinity is +142 kJ.Electron affinity is -710 kJ.Electron affinity is +710 kJ.Process is endothermic.Process involves single electron addition.Reactions = Cl(g)+e−→Cl−(g), O(g)+e−→O−(g) , O−(g)+e−→O2−(g), All three of the reactions, None of the reactions

Answer 1

Answer:

.Electron affinity is -142 kJ<---------->O(g)+e−→O−(g)Process involves single electron addition

O−(g)+e−→O2−(g)<--------> Electron affinity is +710 kJ. .Process is endothermic

Cl(g)+e−→Cl−(g)=Electron affinity is -349 kJ. Process involves single electron addition

None of the of thee reactions ----------Electron affinity is +142 kJ.

Explanation:

Negative electron affinity values indicate that energy is given out when the atom accepts an electron. Halogens evolve a large amount of heat on forming halide ions.

Substantial amount of energy is absorbed when two electrons are added to O2- thus its electron affinity has a positive sign. Energy is evolved on adding only one electron to form O- is hence it has a negative value of electron affinity as shown.