Electron Gain Enthalpy and its Applications

Name the element with maximum electron affinity.

The electronic configuration of four elements I, II, III and IV are given:

I $: 1{\mathrm{s}}^2 2{\mathrm{s}}^2 2{\mathrm{p}}^5$

II $: 1{\mathrm{s}}^2 2{\mathrm{s}}^2 2{\mathrm{p}}^4$

III $: 1{\mathrm{s}}^2 2{\mathrm{s}}^2 2{\mathrm{p}}^6 3{\mathrm{s}}^2 3{\mathrm{p}}^5$

IV $:$ $1{\mathrm{s}}^2 2{\mathrm{s}}^2 2{\mathrm{p}}^6 3{\mathrm{s}}^2 3{\mathrm{p}}^3$

Which element has highest value of $1^{\text{st }}$ Electron gain enthalpy (magnitude):

Correct statement is ?

The formation of the oxide ion ${\mathrm{O}}^{2-}$(g) requires first an exothermic and then an endothermic step as shown below: $\mathrm{O}\left(\mathrm{g}\right)+{\mathrm{e}}^{-1}\to {\mathrm{O}}^{-}\left(\mathrm{g}\right);∆{\mathrm{H}}^0=-142 \mathrm{k}\mathrm{J} \mathrm{m}\mathrm{o}{\mathrm{l}}^{-1}$
${\mathrm{O}}^{-}\left(\mathrm{g}\right)+{\mathrm{e}}^{-1}\to {\mathrm{O}}^{2-}\left(\mathrm{g}\right);∆{\mathrm{H}}^0=+844 \mathrm{k}\mathrm{J} \mathrm{m}\mathrm{o}{\mathrm{l}}^{-1}$
This is because

Explain periodicity in electron gain enthalpy in a group? 

Which one (atom / ion) in the following pairs has higher electron gain enthalpy?
${\mathrm{N}}^{-}, \mathrm{P}$

Which one (atom / ion) in the following pairs has higher electron gain enthalpy?
${\mathrm{O}}^{-}, {\mathrm{S}}^{-}$

Which one (atom / ion) in the following pairs has higher electron gain enthalpy?
$\mathrm{O}, {\mathrm{S}}^{-}$

Which one (atom / ion) in the following pairs has higher electron gain enthalpy?
 $O^{-},S$ 

Energy will be released in which of the following?

Among the following, Which will have lowest electron affinity ?

When 2 gm of chlorine is completely converted to Cl^- ion in a gaseous state, the amount of energy released in K Cal is:
Note: Chlorine has electron affinity 3.7 eV. $(1\mathrm{e}.\mathrm{V}=23.06\mathrm{K}. \mathrm{Cal}{\mathrm{mol}}^{-1})$

Arrange these elements in the increasing order of the magnitude (without sign) of their electron affinity or electron gain enthalpy based on their electronic configurations given below-

1. $2{\mathrm{s}}^{2}2{\mathrm{p}}^5$

2. $3{\mathrm{s}}^{2}3{\mathrm{p}}^5$

3. $2{\mathrm{s}}^{2}2{\mathrm{p}}^4$

4. $3{\mathrm{s}}^{2}3{\mathrm{p}}^4$

Find the correct order of electron gain enthalpy ($∆{}_{\mathrm{eg}}\mathrm{H}$) of the given elements.

Among the following, which is correctly represented the order of electron gain enthalpy?

Among the following, which process does not involve absorption of energy?

$\mathrm{EA}$ values of $\mathrm{N}$ and $\mathrm{P}$ are exceptionally low, because:

The first $\left({∆}_{\mathrm{i}}{\mathrm{H}}_1\right)$ and the second $\left({∆}_{\mathrm{i}}{\mathrm{H}}_2\right)$ ionization enthalpies $\left(\mathrm{in} \mathrm{kJ} {\mathrm{mol}}^{-1}\right)$ and the $∆{\mathrm{e}}_{\mathrm{g}} \mathrm{H}$ electron gain enthalpy $\left(\mathrm{in} \mathrm{kJ} {\mathrm{mol}}^{-1}\right)$ of a few elements are given below:
 

Which of the above is likely to be the least reactive non-metal?

(Write the correct element number from the above list as the answer)

In which of the following transformation the least energy is required?

In which process maximum energy is released?