Question #5f528

1 Answer
Jun 23, 2017

The process involving the maximum amount of energy is c) #"O"^"-" + "e"^"-" → "O"^"2-"#.


The first electron affinity is the amount of energy released or absorbed when an electron is added to a neutral atom in the gaseous state.

#"X(g)" + "e"^"-" → "X"^"-""(g)"#

As you might expect, the electron affinity becomes more negative from left to right across a row in the Periodic Table.

Thus, the order of first electron affinities is

#"N < O < F"#

The numbers are +7, -141, and—328 kJ/mol, respectively.

The second electron affinity is the energy required to add an electron to a
gaseous 1- ion.

#"X"^"−""(g)" + "e"^"-" → "X"^"2-""(g)"#

You are forcing an electron into an already negative ion. It's not going to go in willingly!

Thus, for the second electron affinity of oxygen,

#"O"^"-""(g)" + "e"^"-" → "O"^"2-""(g)"; EA = "+844 kJ/mol"#

This is the maximum amount of energy absorbed or released.

Hence, the correct answer is c).