Ans :
- Chemicals in the solution to be analysed are in an unknown amount in the solution. In the presence of an indicator (most commonly phenolphthalein).
- A reagent with an unknown concentration reacts with a chemical with an unknown amount to reveal the end-point concentration. It is the point at which the reaction is said to have come to a close.
- Titration is used to determine the volumes because it allows the reaction between the solution and the reagent to be completed.