1. Acid-Base Titration
Titration is a chemical analysis involving the addition of a known concentration of titrant to a known volume but unknown concentration of sample.
Acid-Base titration, involves a reaction between an acid and base resulting in the production of water and a salt (neutralization).
In a titration, an indicator is used to determine the end point of the reaction.
At the end point, the indicator will change colour.
The equivalence point or stoichiometric point occurs when equal moles of hydronium and hydroxide ions have been reacted to produce water.
The equivalence point is not always equal to the end point and does not always occur at a pH of 7.
When choosing an indicator for a titration, one tries to chose an indicator that will change when the equivalence point is reached.

2. Titration Between a Strong Acid and Base
Indicators – organic molecules with the ability to change colour depending upon the pH of a solution.
Titration Between a Strong Acid and Base
The equivalence point will occur at a pH of 7.
Want an indicator that will change around 7.
Titration Between a Weak Acid and Strong Base
The equivalence point will occur at a pH above
Want an indicator that will change above 7.
Titration Between a Strong Acid and Weak Base
The equivalence point will occur at a pH below 7.
Want an indicator that will change below7.