Enter the conjugate base, acid [HA], and dissociation constant into the calculator to calculate the pH of a solution.

- Arrhenius Equation Calculator
- Molarity Calculator
- Dilution Calculator
- Vapor Pressure Calculator (Solvent/Solution)

## Henderson Hasselbalch Formula

The following formula is used to calculate the pH of a solution using the Henderson Hasselbalch equation.

pH = Kₐ + log([A⁻]/[HA])

- Ka is the acid dissociation constant
- A- is the molar concentration of the base in molars
- HA is the molar concentration of the acid in molar

pH is a measure of the solutions acidity of a solution.

## Henderson Hasselbalch Equation Definition

**What is the Henderson Hasselbalch equation? **The Henderson Hasselbalch equation is a formula used to calculate the pH (acidity) of a buffer. The equation is denoted: pH = Kₐ + log([A⁻]/[HA]).

**What is a buffer? **A buffer is a mixture or solution that contains a weak acid and a conjugate base. The combination of these two components, while at equilibrium,

## How to calculate buffer pH?

The following is an example problem that uses the Henderson-Hasselbalch equation to determine the pH of a buffer.

- First, determine the acid dissociation constant. For this example, the acid dissociation constant is found to be 3.
- Next, determine the molar concentration of the base. The molar concentration is found to be or 3 moles per liter.
- Next, determine the molar concentration of the acid. For this problem, the molar concentration of the acid is found to be 4 moles per liter.
- Finally, calculate the buffer pH. Using the formula, the buffer pH is found to be 3 + log ( 3/4) =

**Does the henderson-hasselbalch equation work for bases? **The henderson-hasselbalch equation is used to find the pH values for buffer solutions, which are acid-base solutions, so the equation itself is used to bases.

**When does the henderson-hasselbalch equation fail? **The equation does not work in situations where the buffer solutions are highly diluted through the water.