1. What is pH at Equivalence Point?

The equivalence point in a titration is when the amount of titrant added is exactly enough to completely neutralize the analyte solution. The pH at this point depends on the type of acid-base titration being performed.

2. How Does the Calculator Work?

The calculator uses different formulas based on titration type:

Where:

• \( pKw \) — Water dissociation constant (14.00 at 25°C)
• \( pKa \) — Acid dissociation constant
• \( pKb \) — Base dissociation constant

Explanation: The pH at equivalence point depends on the nature of the resulting salt. Strong acid-strong base titrations produce neutral salts (pH=7), while weak acid or weak base titrations produce basic or acidic salts respectively.

3. Importance of pH Calculation

Details: Knowing the expected pH at equivalence point helps in selecting appropriate indicators for titration experiments and understanding the neutralization process in acid-base reactions.

4. Using the Calculator

Tips: Select the titration type and provide pKa or pKb values when required for weak acid or weak base titrations. All values should be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is pH=7 for strong acid-strong base titration?
A: Because the salt formed is neutral and doesn't hydrolyze in water, resulting in a pH of 7.

Q2: Why does weak acid-strong base titration have pH>7?
A: The conjugate base of the weak acid hydrolyzes water, producing OH⁻ ions and making the solution basic.

Q3: What is the value of pKw?
A: pKw is 14.00 at 25°C, but it varies with temperature. This calculator uses the standard value of 14.00.

Q4: Can I use this calculator for polyprotic acids?
A: This calculator is designed for monoprotic acids and monobasic bases. For polyprotic systems, the calculation is more complex.

Q5: How accurate is this calculation?
A: The calculation provides theoretical values. Actual experimental results may vary due to concentration, temperature, and ionic strength effects.