How to Calculate pH of Sodium Acetate Solution

What is the process to calculate the pH of a sodium acetate solution?

How does the concentration of sodium acetate affect the pH of the solution?

Calculation Method for pH of Sodium Acetate Solution

When it comes to determining the pH of a sodium acetate solution, the key lies in understanding the ionization of a weak base and leveraging the known ionization constant of acetic acid, Ka.

Calculating the pH of a sodium acetate solution involves recognizing the dissociation of the compound into acetic acid and hydroxide ions in water. By considering sodium acetate as a base in this context, we can establish the equilibrium expression as Kb = [OH-][HC₂H3O2]/[NaC2H3O2], where Kb represents the base ionization constant.

Given that Kw = Ka x Kb and Kw is the ion-product of water (1.0x10^-14 at 25°C), with the provided Ka value for acetic acid, we can compute Kb. Following this, through the ionization expression for a weak base (OH-) = √(Kb x 0.149), we ascertain the pOH by -log[OH-]. Since pH + pOH = pKw = 14, it becomes feasible to calculate the pH of the solution.

By understanding this methodology, you can unlock the ability to determine the pH of sodium acetate solutions with confidence and precision.