When table salt (sodium chloride, NaCl) is added to water, it dissolves due to the interaction between the salt and water molecules. This process can be explained through several key points:
- Water Molecules Hydrogen Bonding with Sodium and Chloride Ions: Water is a polar molecule, meaning it has a positive end (hydrogens) and a negative end (oxygen). When NaCl is introduced to water, the positive ends of the water molecules are attracted to the negatively charged chloride ions (Cl–), while the negative ends of the water molecules are attracted to the positively charged sodium ions (Na+). This attraction leads to the formation of hydrogen bonds between water molecules and the ions, pulling them away from the solid structure of the salt.
- Each Sodium Ion Surrounded by Chloride Ions: As the Na+ ions are pulled into solution, they become surrounded by water molecules. At the same time, it is essential to note that the Cl– ions are also surrounded by water molecules. This sphere of hydration effectively keeps the ions separated, ensuring that they do not reassemble into solid salt.
- Each NaCl Molecule Surrounded by Water Molecules: In the solution process, individual NaCl pairs dissociate, with each sodium ion surrounded by water molecules in a specific orientation determined by the polarity of water. As more NaCl is added, the process continues until saturation is reached, meaning no more salt can dissolve in the water.
In conclusion, the dissolution of sodium chloride in water is a result of the electrostatic interactions between the water molecules and the ions, which leads to the breakdown of the ionic lattice structure of solid salt.