Solvation
Solvation is the process of surrounding solute particles with solvent molecules, leading to the formation of a solution.
It involves:
Breaking Solute-Solute Interactions:
Energy is required to separate solute molecules from each other.
Breaking Solvent-Solvent Interactions:
Energy is needed to create space within the solvent by disrupting solvent-solvent interactions.
Formation of Solute-Solvent Interactions:
Solute particles are surrounded by solvent molecules, forming stable solute-solvent interactions, which release energy.
Solvation States
Fully Solvated:
Solute particles are completely surrounded by solvent molecules.
Maximum interaction between solute and solvent.
Partially Solvated:
Solute particles are partially surrounded by solvent molecules.
Some solute-solute interactions may still exist.
Contracted:
Solute particles are minimally surrounded by solvent molecules.
Solute-solute interactions dominate, with limited solute-solvent interactions.
These states describe the extent of interaction between solute particles and solvent molecules during the solvation process.
Association
Association refers to the interaction between solute molecules within a solution, which can influence solubility and other properties.
Types of associations include:
Hydrogen Bonding:
Strong interactions between molecules containing hydrogen bonded to electronegative atoms like oxygen or nitrogen.
Ion Pairing:
Formation of ion pairs in ionic solutes, which can affect solubility, especially in polar solvents.
Van der Waals Forces:
Weak interactions, such as London dispersion forces, between non-polar molecules or parts of molecules.