* Polarity: Water is a polar molecule, meaning it has a positive end and a negative end due to the uneven sharing of electrons. Ionic compounds are also polar, with their positive and negative ions attracted to each other.
* Attraction: When an ionic compound like NaCl is placed in water, the positive end of water molecules (hydrogen) is attracted to the negative chloride ions (Cl-), and the negative end of water molecules (oxygen) is attracted to the positive sodium ions (Na+).
* Solvation: This attraction overcomes the forces holding the ions together in the crystal lattice. The water molecules surround the ions, effectively separating them and keeping them dissolved.
Key Point: The ability of an ionic compound to dissolve in water depends on the relative strength of the attraction between the ions and the water molecules compared to the attraction between the ions themselves.
Factors affecting solubility:
* Lattice energy: The stronger the attraction between ions in the crystal lattice, the less soluble the compound will be.
* Hydration energy: The stronger the attraction between ions and water molecules, the more soluble the compound will be.
Sodium chloride has a relatively low lattice energy and a high hydration energy, making it very soluble in water.
