Upon hydrolysis of sodium carbonate, the reaction takes place between :-Na+ and waterNa+ and OH– and water and H+

Upon hydrolysis of sodium carbonate (Na2CO3), the reaction takes place between the carbonate ion (CO3^2-) and water (H2O). Sodium ions (Na+) are spectator ions in this reaction, meaning they do not participate in the reaction.

Here's the step-by-step process:

1. Sodium carbonate (Na2CO3) dissolves in water to form sodium ions (Na+) and carbonate ions (CO3^2-).

   Na2CO3 (s) → 2Na+ (aq) + CO3^2- (aq)

2. The carbonate ions (CO3^2-) then react with water (H2O) to form bicarbonate ions (HCO3-) and hydroxide ions (OH-).

   CO3^2- (aq) + H2O (l) → HCO3- (aq) + OH- (aq)

So, the reaction upon hydrolysis of sodium carbonate takes place between carbonate ions (CO3^2-) and water (H2O), not between Na+ and water or Na+ and OH– and water and H+.