Question

Which the following is exothermic process and why?
1: Be + e- ----> Be^-
2: Li + e- -----> Li^-
3: Na -----> Na^+ + e-
4: N + e- -----> N + e -
Here all atoms are gaseous atoms

Answer 1

Question #57801, Chemistry, Other

Which the following is exothermic process and why?

1: Be + e⁻ → Be⁻

2: Li + e⁻ → Li⁻

3: Na → Na⁺ + e⁻

4: N⁺ + e⁻ → N + e⁻

Here all atoms are gaseous atoms

Answer:

4. Thermal effect of the listed reactions is dependant of the electron affinity of each element. In order to take an electron from the Na atom the energy is needed. That is why this reaction will be endothermic. From the listed ones Li and Be have low electron affinity; N – high electron affinity. So that adding electron to N atom will lead to the release of energy.