Electron Affinity and Electron Gain Enthalpy: Differences and Explanations

Introduction:

Electron affinity and electron gain enthalpy are two important concepts in chemistry. Both concepts are related to the ability of atoms to gain electrons. However, there are some differences between these two concepts.

Electron Affinity:

Electron affinity is defined as the energy change that occurs when an atom gains an electron to form a negative ion. It is a measure of the attraction between the nucleus of an atom and the added electron. Electron affinity is usually expressed in kilojoules per mole (kJ/mol). A positive value of electron affinity indicates that energy is released when an electron is added to the atom, while a negative value indicates that energy is required to add an electron to the atom.

Electron Gain Enthalpy:

Electron gain enthalpy is defined as the energy change that occurs when an isolated gaseous atom gains an electron to form a negative ion. It is the enthalpy change for the process of adding an electron to an isolated gaseous atom. Like electron affinity, electron gain enthalpy is also expressed in kilojoules per mole (kJ/mol). A negative value of electron gain enthalpy indicates that energy is released when an electron is added to the atom, while a positive value indicates that energy is required to add an electron to the atom.

Differences:

There are some differences between electron affinity and electron gain enthalpy, which are as follows:

1. Definition: Electron affinity is defined as the energy change that occurs when an atom gains an electron to form a negative ion, while electron gain enthalpy is defined as the energy change that occurs when an isolated gaseous atom gains an electron to form a negative ion.

2. Reference State: Electron affinity is measured in the solid state, while electron gain enthalpy is measured in the gaseous state.

3. Magnitude: The magnitude of electron affinity is usually greater than that of electron gain enthalpy.

4. Sign: The sign of electron affinity can be both positive and negative, while the sign of electron gain enthalpy is always negative.

Conclusion:

In conclusion, electron affinity and electron gain enthalpy are two important concepts in chemistry that are related to the ability of atoms to gain electrons. While there are some differences between these two concepts, both are important in understanding the chemical behavior of atoms.

When energy is supplied to an atom while adding an electron. Electron affinity means love for electron. It is the negative of the electron gain enthalpy. Electron Gain enthalpy is the energy released when an isolated gaseous atom accepts an electron to covert into an anion.