Calculate The Ph Of A Buffer Solution Containing

Henderson-Hasselbalch Equation:

\[ pH = pKa + \log\left(\frac{[base]}{[acid]}\right) \]

pH:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Henderson-Hasselbalch Equation?

The Henderson-Hasselbalch equation is used to estimate the pH of a buffer solution from the pKa of the acid and the concentrations of the base and acid components. It provides a simple way to calculate the pH of buffer systems in chemistry and biology.

2. How Does the Calculator Work?

The calculator uses the Henderson-Hasselbalch equation:

\[ pH = pKa + \log\left(\frac{[base]}{[acid]}\right) \]

Where:

\( pH \) — pH value (dimensionless)
\( pKa \) — Acid dissociation constant (dimensionless)
\( [base] \) — Concentration of base (mol/L)
\( [acid] \) — Concentration of acid (mol/L)

Explanation: The equation relates the pH of a solution to the pKa and the ratio of the concentrations of the conjugate base and weak acid.

3. Importance of pH Calculation

Details: Accurate pH calculation is crucial for understanding buffer capacity, predicting chemical behavior, and maintaining stable pH conditions in biological and chemical systems.

4. Using the Calculator

Tips: Enter pKa value, base concentration and acid concentration in mol/L. All concentration values must be greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What is the valid range for pH values?
A: pH values typically range from 0 to 14, with 7 being neutral. Values below 7 are acidic and above 7 are basic.

Q2: When is the Henderson-Hasselbalch equation most accurate?
A: The equation is most accurate when the concentrations of acid and base are relatively high and similar in magnitude, typically within one order of magnitude of each other.

Q3: What are common buffer systems that use this equation?
A: Common buffer systems include acetate (acetic acid/acetate), phosphate (H₂PO₄⁻/HPO₄²⁻), and carbonate (H₂CO₃/HCO₃⁻) buffers.

Q4: Are there limitations to this equation?
A: The equation assumes ideal behavior and may be less accurate at extreme pH values, very low buffer concentrations, or when ionic strength is high.

Q5: How does temperature affect the calculation?
A: Temperature affects both pKa values and pH measurements. The pKa value used should be appropriate for the temperature at which the measurement is made.