BackAcid-Base Titration Calculator
Background
The Acid-Base Titration Calculator determines the pH at different stages of a titration between acids and bases. It takes into account the concentration and volume of both titrant and analyte and calculates the pH based on the type of acid-base reaction. For weak acids or bases, it uses the dissociation constant (Ka or Kb) and applies the Henderson-Hasselbalch equation or hydrolysis principles as necessary. This tool helps chemistry students visualize the pH change during a titration, including the buffer region and equivalence point.
How to use Acid-Base Titration Calculator
Select the type of titration, enter the volume and concentration of the acid/base and titrant, and (if applicable) the Ka or Kb value. Click Calculate to see the pH and region (buffer, equivalence, etc.).
- Titration is based on the neutralization reaction between an acid and a base.
- The equivalence point is reached when moles of acid = moles of base.
- The titration formula helps calculate unknown concentrations.
Formula & Equation Used
Key formulas used in this calculator:
- pH = -log₁₀([H⁺])
- pOH = -log₁₀([OH⁻])
- pH = 14 - pOH
- pH = pKa + log₁₀([A⁻]/[HA]) (buffer region)
Example Problem & Step-by-Step Solution
Problem:
Calculate the pH after adding 15.0 mL of 0.100 M NaOH to 25.0 mL of 0.100 M HCl.
- Moles of HCl = 0.025 L × 0.100 mol/L = 0.0025 mol
- Moles of NaOH = 0.015 L × 0.100 mol/L = 0.0015 mol
- Remaining HCl = 0.0025 mol − 0.0015 mol = 0.0010 mol
- Total volume = 25.0 + 15.0 = 40.0 mL = 0.040 L
- [H⁺] = 0.0010 / 0.040 = 0.025 M
- pH = -log₁₀(0.025) = 1.60
Final Answer: pH ≈ 1.60
