Ionization Enthalpy: Introduction

Ionization enthalpy is the energy required to remove an electron from an atom or ion in its gaseous state. It is a measure of the strength of attraction between the nucleus and the outermost electron. The higher the ionization enthalpy, the more difficult it is to remove an electron from an atom.

Comparison between Fe2+ and Fe3+

In the case of Fe2+ and Fe3+, both are ions of iron, but Fe2+ has two fewer electrons than Fe3+. Let's compare their ionization enthalpies to determine which has a higher value.

Explanation: Ionization Enthalpy of Fe2+

1. Fe2+ is an ion that has lost two electrons from its neutral iron atom. The ionization enthalpy of Fe2+ is the energy required to remove an additional electron from Fe2+ to form Fe3+.

2. Fe2+ has a higher ionization enthalpy compared to neutral iron (Fe) because it has already lost two electrons. The remaining electrons are held more tightly due to increased electrostatic attraction from the now positively charged nucleus.

3. Removing an electron from Fe2+ requires overcoming the electrostatic attraction between the remaining electron(s) and the nucleus, which demands a significant amount of energy.

4. Therefore, Fe2+ has a higher ionization enthalpy compared to Fe3+ as it requires more energy to remove an electron from Fe2+ to form Fe3+.

Explanation: Ionization Enthalpy of Fe3+

1. Fe3+ is an ion that has lost three electrons from its neutral iron atom. The ionization enthalpy of Fe3+ is the energy required to remove an additional electron from Fe3+.

2. Fe3+ has a lower ionization enthalpy compared to Fe2+ because it has already lost three electrons, resulting in a decrease in the electrostatic attraction between the remaining electron(s) and the nucleus.

3. The reduced electrostatic attraction makes it easier to remove an electron from Fe3+ compared to Fe2+, as the positive charge of the nucleus is spread over a larger area due to the loss of three electrons.

4. Therefore, Fe3+ has a lower ionization enthalpy compared to Fe2+, indicating that it requires less energy to remove an electron from Fe3+.

Conclusion

In conclusion, Fe2+ has a higher ionization enthalpy compared to Fe3+ because it has already lost two electrons and the remaining electrons are held more tightly. Fe3+ has a lower ionization enthalpy as it has already lost three electrons, resulting in a reduced electrostatic attraction between the remaining electron(s) and the nucleus.

Ans: fe +3 (26 is its atomiic no. )((26 -3 it will be 23 nd 26 - 2 it will be 24 ))fe +3 has highest ionization enthalpy bcoz ..increase in atomic no. it has less IE .. while decrease in atomic number more IE