Dissolution:
1. Ionization: The strong ionic bonds holding the sodium (Na+) and chloride (Cl-) ions together in the NaCl crystal lattice are disrupted by the polar water molecules.
2. Hydration: The positive end of the water molecule (hydrogen) is attracted to the negatively charged chloride ions (Cl-), while the negative end of the water molecule (oxygen) is attracted to the positively charged sodium ions (Na+). This attraction forms hydration shells around the ions, effectively pulling them apart from the crystal lattice.
3. Dissociation: As the hydration process continues, the Na+ and Cl- ions become completely surrounded by water molecules, separating them from each other and allowing them to move freely in the solution. This process is called dissociation.
Result:
* The NaCl dissolves in water, forming a homogeneous solution.
* The solution conducts electricity because of the presence of free ions (Na+ and Cl-).
* The water becomes slightly salty.
Important Note:
* The dissolving process is an endothermic reaction, meaning it absorbs heat from the surroundings. This is why adding salt to water can lower the freezing point and raise the boiling point.
* Not all salts dissolve in water to the same extent. The solubility of a salt depends on factors such as temperature, the strength of the ionic bonds, and the polarity of the solvent.
