Sodium Phosphate Buffer Calculator

Sodium Phosphate Buffer Equation:

\[ \text{Ratio} = 10^{\text{pH} - \text{pKa}} \]

Ratio:

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1. What is the Sodium Phosphate Buffer Equation?

The Sodium Phosphate Buffer equation calculates the ratio of conjugate base to weak acid in a phosphate buffer system using pH and pKa values. This ratio is essential for preparing buffer solutions with specific pH values.

2. How Does the Calculator Work?

The calculator uses the Sodium Phosphate Buffer equation:

\[ \text{Ratio} = 10^{\text{pH} - \text{pKa}} \]

Where:

\( \text{pH} \) — pH value of the buffer solution (dimensionless)
\( \text{pKa} \) — Acid dissociation constant (dimensionless)

Explanation: The equation calculates the ratio of [A⁻]/[HA] based on the Henderson-Hasselbalch equation, which is fundamental for buffer preparation.

3. Importance of Buffer Ratio Calculation

Details: Accurate buffer ratio calculation is crucial for preparing laboratory buffer solutions with precise pH values, maintaining stable pH conditions in biochemical experiments, and ensuring proper buffer capacity.

4. Using the Calculator

Tips: Enter pH and pKa values as dimensionless numbers. Both values must be valid numerical inputs.

5. Frequently Asked Questions (FAQ)

Q1: What is the significance of the buffer ratio?
A: The buffer ratio determines the proportion of conjugate base to weak acid needed to achieve a specific pH in a buffer solution.

Q2: What is the typical pKa value for phosphate buffer?
A: The phosphate buffer system has three pKa values (2.14, 7.20, and 12.67). The second pKa (7.20) is most commonly used for biological buffers.

Q3: How accurate is this calculation?
A: The calculation provides a theoretical ratio based on ideal conditions. Actual buffer preparation may require minor adjustments due to ionic strength and temperature effects.

Q4: Can this calculator be used for other buffer systems?
A: While the equation is general for any acid-base buffer system, this calculator is specifically designed for phosphate buffers using their characteristic pKa values.

Q5: What factors affect buffer capacity?
A: Buffer capacity depends on the total concentration of the buffer components and how close the ratio is to 1:1 (when pH = pKa).