Buffer pH Calculator
Calculate the pH of a buffer solution composed of a weak acid and its conjugate base.
Calculation Parameters
Adjust the values below.
Calculated Result
Expert Tip
Ensure units are correctly formatted (e.g. Kelvin for gas temperatures and liters for volumes) to get chemically accurate outputs.
How this Calculator Works
This calculator allows you to solve Buffer pH problems dynamically. Adjust the input parameters using the sliders or selection menu below:
- Weak Acid Concentration (M) (Range: 0.01 to 2.00, Default: 0.10)
- Conjugate Base Concentration (M) (Range: 0.01 to 2.00, Default: 0.10)
- pKa of Weak Acid (Range: 0 to 14, Default: 4.75)
The results are computed instantly and updated in the results panel on the right.
Formula & Methodology
Where:
- Weak Acid Concentration: Parameter value.
- Conjugate Base Concentration: Parameter value.
- pKa of Weak Acid: Parameter value.
Step-by-Step Calculation Example
To calculate Buffer pH manually, follow these steps:
- Identify the input parameters. For example:
- Weak Acid Concentration (M) = 0.10
- Conjugate Base Concentration (M) = 0.10
- pKa of Weak Acid = 4.75
- Apply the formula:
pH = pKa + log10([Conjugate Base] / [Weak Acid])
- Verify the calculated value which is updated instantly in the results panel on the right.
Frequently Asked Questions
What is a buffer solution? ▼
A buffer solution consists of a weak acid and its conjugate base that resists drastic pH changes upon addition of small amounts of acid or base.
How do you calculate buffer pH? ▼
Use the Henderson-Hasselbalch equation: pH = pKa + log10([Conjugate Base] / [Weak Acid]).
What is the effective pH range of a buffer? ▼
A buffer is effective within ±1.0 pH unit of the weak acid's pKa value.