Titration
Year 10 (IGCSE) 🧪 Acids, Bases & Salts Perform acid-base titration calculations using C₁V₁ = C₂V₂.
🧪 Acid-Base Titration
Titration finds the exact volume of one solution needed to react completely with a known volume of another.
- Fill burette with standard solution (known concentration) to 0.00 cm³.
- Pipette exact volume of analyte into conical flask; add indicator.
- Add standard solution slowly; swirl until indicator just changes colour permanently (end point).
- Record titre. Repeat until results are concordant (within 0.10 cm³).
🧮 Titration Calculations
1:1 Mole Ratio
$$C_1 V_1 = C_2 V_2$$Example: 25.0 cm³ of 0.1 mol/dm³ NaOH neutralises 12.5 cm³ HCl. Find [HCl].
n(NaOH) = 0.1 × 0.025 = 0.0025 mol
NaOH:HCl = 1:1 → n(HCl) = 0.0025 mol
C(HCl) = 0.0025/0.0125 = 0.2 mol/dm³
n(NaOH) = 0.1 × 0.025 = 0.0025 mol
NaOH:HCl = 1:1 → n(HCl) = 0.0025 mol
C(HCl) = 0.0025/0.0125 = 0.2 mol/dm³
🌈 Indicators
Adding distilled water to the flask is fine — it does not change the number of moles of analyte.
Phenolphthalein: colourless → pink at pH 8.2–10. Strong acid + strong base.
Methyl orange: red → orange at pH 3.1–4.4. Strong acid + weak base.
Methyl orange: red → orange at pH 3.1–4.4. Strong acid + weak base.
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Interactive Demonstration — Titration
🧪 Titration Calculator
Use C₁V₁ = C₂V₂ for 1:1 acid-base reactions.