The Setup

A titration is a procedure that involves using an acid or base with a known concentration to determine the concentration of another acid or base with an unknown concentration.

Typically, the standard solution is placed in the burette, and the pipetted analyte and indicator are placed in the conical flask. However, the standard solution and analyte can be in either the burette of flask. The setup for conducting a titration is shown below:

Before beginning a titration, an initial burette volume must be recorded. The titration begins by opening the burette tap slightly, allowing the standard solution to react with the analyte solution. After the end point has been reached, the burette tap is closed, and the final burette volume is recorded. The initial burette volume should be subtracted from the final burette volume to give the titre volume. This is the volume required to reach the end point of the titration.

The first trial is usually used to estimate the titre volume required to reach the end point. At least three subsequent trials are more accurately carried out to achieve three concordant titre volumes (i.e. volumes which are within 0.1 mL of each other). Additional trials should be carried out until these three concordant titres are achieved.

Calculating the Average Titre Volume

An average of the three concordant titre volumes will be calculated to give the average titre volume of the titration. For example:

This average titre volume will be used to help calculate the unknown concentration.