Application of Hydration Enthalpy

Hydration enthalpy is the quantity of energy produced when 1 mole of gaseous ions is mixed with H2O to produce hydrated ions. Hydration energy is a significant component in the brief analysis of solvation. When salt is dissolved in H2O (water), the topmost ions break away from its lattice and are covered by the water molecules around them. The salt is water-soluble if the hydration value is equal to or better than the lattice energy. 

Hydration Enthalpy of Elements

The hydration enthalpy is proportional to the charge density of ions. The charge density of smaller ions is higher. Hence the hydration enthalpy of smaller ions is higher. The attractive force between the ion and the polar water end increases as the charge density increases. Smaller ions have a greater hydration enthalpy value due to this. The alkali metals were highly hydrated, and the degree of hydration diminishes as you move through the group.

Write down the Application of Hydration Enthalpy

The reaction of water and cement is one use of enthalpy of hydration. Because the process is exothermic, a lot of heat is released. The heat emitted in mass constructions such as dams and other structures become significant. Large amounts of cement are utilised in the building of enormous concrete blocks. The heat is produced during the setting process. The exterior edges of the brick cool quicker than the inside, resulting in a temperature gradient in the brick that can lead to cracks and structural failure. To avoid this challenge, low-heat types of cement, cement containing pozzolanic admixtures such as fly ash or slag, and concrete prepared with ice rather than water are favoured for enormous construction.

What factors affect the size of hydration enthalpy?

The force of attraction is generally high in the case of the smaller ions. The hydration enthalpies, for example, decrease as we progress down the periodic table. The little lithium-ion has the highest hydration enthalpy in Group 1 of the periodic table, whereas the smaller fluoride ion has the maximum hydration enthalpy in Group 7. As the ions increase bigger, the hydration enthalpy decreases in both groups.

Another crucial factor that affects the hydration enthalpy of elements is the Ionic radius. As we reduce the radius of the ion, ΔHhydθgets more exothermic. In small elements, the charge density is extremely high, making the ion-dipole attraction stronger between ions and water molecules in the solution. The system becomes hydrated, due to which it releases more energy. As a result, it became more exothermic. 

The charge of the ion is directly proportional to the force of attraction between them, i.e., attraction became stronger with the increase in the charge. For example, Group 2 ions (such as Mg2+) have substantially greater hydration enthalpies than Group 1 ions (Na+).

Conclusion

We all are well aware of the term hydration enthalpy. Hydration enthalpy is the quantity of energy produced when 1 (one) mole of the gaseous ions is mixed with H2O (water) to produce hydrated ions. Hydration energy is a significant component in the brief analysis of solvation. There are several applications of hydration enthalpy, and the most critical application of the hydration enthalpy is the reaction of water, and cement is one use of enthalpy of hydration.