Introduction:
Sodium chloride (NaCl) is a compound composed of sodium (Na) and chloride (Cl) ions, while distilled water is a pure form of water that does not contain any dissolved ions. The ability to conduct electricity in a substance depends on the presence of free-moving charged particles called ions.

Explanation:
1. Sodium chloride:
When sodium chloride is dissolved in water, it dissociates into its constituent ions, sodium (Na+) and chloride (Cl-) ions. These ions are free to move within the solution, making it an electrolyte. When an electric potential is applied across the solution, the positive sodium ions migrate towards the negative electrode (cathode), while the negative chloride ions migrate towards the positive electrode (anode). This movement of charged particles constitutes an electric current, allowing sodium chloride solution to conduct electricity.

2. Distilled water:
Distilled water, on the other hand, does not contain any dissolved ions. It undergoes the process of distillation, which removes impurities and minerals, including ions. As a result, distilled water does not have free-moving charged particles necessary for conducting electricity. It is considered a non-electrolyte.

Comparison:
The key difference lies in the presence of ions. Sodium chloride solution contains dissociated ions, which act as charge carriers, facilitating the flow of electricity. Distilled water, lacking ions, does not have this ability. The ions in sodium chloride solution allow the passage of electric current, while distilled water, being a non-electrolyte, does not conduct electricity.

Conclusion:
In summary, sodium chloride can conduct electricity because it dissociates into ions when dissolved in water, allowing the movement of charged particles. On the other hand, distilled water, being an ion-free substance, does not possess the ability to conduct electricity.

Sodium chloride conduct electricity but distilled water do not because when sodium chloride is added to a electrolyte or electrolysis then it conducts due to the present of salt as salt is there so it makes the water impure and it conducts the electricity but in distilled water it is a pure form of water and no substance is added to it so it do not conduct the electricity if we would add anything to it then it would conduct electricity.