Acid-Base Titration

In the picture

1. 1The burette barrel: holds the titrant and shows the volume delivered.
2. 2The stopcock: controls the flow of titrant drop by drop.
3. 3The conical flask: contains the unknown solution and the indicator, which turns pale pink near the equivalence point.
4. 4The white tile: gives a bright background so the indicator colour is easier to see.

Examples

• Using phenolphthalein to find how much acid is in vinegar.
• Checking the concentration of a cleaning solution by adding titrant until the colour just changes.

Quiz: Acid-Base Titration (Age 17)

1. 1

   In an acid-base titration, what is the stopcock used for?

   • To provide a bright background behind the flask.
   • To hold the titrant and show the volume delivered.
   • To control the flow of titrant drop by drop.
2. 2

   What does the equivalence point mean in a titration?

   • The indicator has permanently changed colour.
   • The burette has been emptied completely.
   • Acid and base have reacted in the exact stoichiometric ratio.
3. 3

   What does the indicator colour change mark during a titration?

   • The point where the burette volume is zero.
   • The end point, which should be as close as possible to the equivalence point.
   • The point where the unknown solution has no indicator left.

The answers, each with its explanation, are in the app. This lesson has left the free week, so its quiz is part of the subscription.