Introduction:
Aqueous solutions can be acidic, basic or neutral depending on the nature of the solute dissolved in water. Sodium chloride and sodium carbonate are two commonly used salts. While an aqueous solution of sodium chloride is neutral, an aqueous solution of sodium carbonate is basic. The reason behind this difference lies in the nature of the salts and their behavior in water.

Sodium Chloride:
Sodium chloride is a simple ionic compound that dissociates into its constituent ions, sodium cation (Na+) and chloride anion (Cl-) in water. These ions are completely soluble in water and do not undergo any hydrolysis. The dissociation of sodium chloride is shown below.

NaCl (s) → Na+ (aq) + Cl- (aq)

As there is no hydrolysis, the solution does not contain any excess of H+ or OH- ions. Hence, the solution is neutral.

Sodium Carbonate:
Sodium carbonate is also an ionic compound, but it undergoes hydrolysis when dissolved in water. The carbonate anion (CO32-) in water reacts with water molecules to form bicarbonate ion (HCO3-) and hydroxide ion (OH-). This hydrolysis reaction is shown below.

CO32- (aq) + H2O (l) → HCO3- (aq) + OH- (aq)

The hydroxide ions produced in this reaction increase the concentration of OH- ions in the solution. This excess concentration of OH- ions makes the solution basic.

Conclusion:
In summary, the nature of the solute and its behavior in water determine whether an aqueous solution is acidic, basic or neutral. Sodium chloride being a simple ionic compound, does not undergo hydrolysis and therefore produces neutral aqueous solution. On the other hand, sodium carbonate undergoes hydrolysis when dissolved in water, producing excess OH- ions, thus making the solution basic.

Sodium chloride is neutral becaise in the formation of sodium chloride strong base and strong acid involve . If hydrochloric acid react with sodium hydroxide so they form sodium chloride and water.
Here sodium carbonate is basic because it formed by strong base sodiom hydroxide react( NaCl) with weak acid carbonic acid (H^2 CO^3)