Acid-base Titrations
Chemistry: Cambridge International GCSE Supplement, topic 12.2.1
Acid-base Titrations
A titration is a method used to find the exact concentration of a solution. It uses precise apparatus to measure liquids accurately.
What is an acid-base titration?
- An acid-base titration is a specific type of titration used to find the concentration of an unknown acid or base.
- It works by neutralising a known volume of the acid with a known concentration of the base (or vice-versa).
- This process relies on a chemical reaction where an acid + base = salt and water.
Titration equipment - Burette
- Burette:
- A long, graduated glass tube with a tap at the bottom.
- It is used to deliver a measured volume of one solution (the titrant) into the flask.
Titration equipment - Volumetric pipette
- Volumetric pipette:
- A tube designed to measure and transfer a fixed, accurate volume of a solution.
- Used to transfer the alkali (or acid) into the conical flask.
Titration equipment - Conical flask
- Conical flask:
- Holds the solution that is being titrated.
- Its shape helps prevent splashing.
Indicator and end-point
- A suitable indicator is a substance that changes colour when the solution changes from acidic to alkaline (or alkaline to acidic).
- Examples:
- Litmus
- Methyl orange
- Phenolphthalein
- The end-point of a titration is the point at which the indicator changes colour to show when neutralisation has occurred.
Test yourself on Acid-base Titrations
Which piece of equipment delivers a measured volume of solution drop by drop during titration?