This topic summary covers Knowledge Organiser: Titrations within Titrations (HT) for GCSE Chemistry. Revise Titrations (HT) in Quantitative Chemistry for GCSE Chemistry with 22 exam-style questions and 20 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 14 of 14 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Knowledge Organiser: Titrations
Key Terms
- Titre: volume added from burette (cm³)
- Concordant: titres within 0.10 cm³
- Endpoint: permanent colour change
- Burette: graduated tube, ±0.05 cm³
- Pipette: fixed volume transfer (25.0 cm³)
- n = c × V: moles from concentration
Must-Know Facts
- Indicator goes in conical flask, not burette
- Read bottom of meniscus at eye level
- Discard rough titration; average concordant results only
- Phenolphthalein: colourless → pink (acid → alkali)
- Methyl orange: red → yellow (acid → alkali)
- Higher Tier: 3-step calculation (n, ratio, c)
Key Equations
- n = c × V (moles = concentration × volume in dm³)
- V(dm³) = V(cm³) ÷ 1000
- c = n ÷ V (find unknown concentration after using mole ratio)
Common Mistakes
- Using volume in cm³ without converting: n = c × V requires volume in dm³ — always divide cm³ by 1000 first
- Averaging all titres including the rough: The rough titration is discarded — only average the concordant results (within 0.10 cm³ of each other)
- Forgetting the mole ratio step: After finding moles of one substance, use the equation's mole ratio before calculating the unknown concentration
- Putting indicator in burette: Indicator always goes in the conical flask — it stays with the solution being titrated, not the solution being added
Practice questions for Titrations (HT)
What is the purpose of a titration?
Explain why the burette should be rinsed with the acid solution before filling it for a titration.
Quick recall flashcards
What are concordant results?
Titration results within 0.10 cm³ of each other
These are the reliable results used to calculate the mean
What is a titration?
A technique to find an unknown concentration by adding a solution of known concentration until the reaction is complete
You measure exactly how much was added