Calculate Ph Of Buffer Solution Containing 0.05

Buffer pH Equation:

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

Calculated pH:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Buffer pH Calculation?

The Henderson-Hasselbalch equation calculates the pH of a buffer solution from the pKa of the acid and the concentrations of the acid and its conjugate base. It provides an accurate estimation of pH for weak acid-base systems.

2. How Does the Calculator Work?

The calculator uses the Henderson-Hasselbalch equation:

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

Where:

\( pH \) — Resulting pH value (dimensionless)
\( pKa \) — Acid dissociation constant (dimensionless)
\( [\text{base}] \) — Concentration of conjugate base (mol/L)
\( [\text{acid}] \) — Concentration of weak acid (mol/L)

Explanation: The equation shows that when base and acid concentrations are equal, pH equals pKa. The pH changes logarithmically with the base-to-acid ratio.

3. Importance of pH Calculation

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

4. Using the Calculator

Tips: Enter pKa value, base concentration, and acid concentration in mol/L. All concentrations must be positive values. The default values represent a 0.05 M buffer solution with equal acid and base concentrations.

5. Frequently Asked Questions (FAQ)

Q1: What happens when base and acid concentrations are equal?
A: When [base] = [acid], the log term becomes log(1) = 0, so pH = pKa exactly.

Q2: What are typical pKa values for common buffers?
A: Common buffer pKa values include: acetate (4.76), phosphate (7.20), Tris (8.06), and carbonate (10.33).

Q3: When is the Henderson-Hasselbalch equation valid?
A: The equation is valid when concentrations are much higher than [H⁺] and [OH⁻], and for weak acids where dissociation is small.

Q4: What is buffer capacity?
A: Buffer capacity refers to the ability of a buffer to resist pH changes when acid or base is added. Maximum buffer capacity occurs when pH = pKa.

Q5: Can this equation be used for strong acids?
A: No, the Henderson-Hasselbalch equation is specifically for weak acid-base pairs and buffer systems.