A titration can be used to determine the unknown concentration of a substance (the "analyte") by slowly adding measured quantities of another substance (the "titrant") which reacts with the analyte in a known proportion. There are several different types of titrations, including acid-base, redox, precipitation, and complex-formation. The titration endpoint can be signaled by an added color-changing substance, an electrical property of the solution, or a visible change to the titrant or analyte. The endpoint corresponds to or is very close to the "equivalence point," the point at which all of the analyte and titrant have reacted, and the volume of titrant used to reach the endpoint can then be used to calculate the analyte concentration.
Learning Objectives
At the end of this module, you will be able to:
- Define the terms "titrant," "analyte," "standard solution," "endpoint," and "equivalence point"
- Identify the variables of the titration equation, and demonstrate how to calculate an unknown concentration based on titration results
- In an acid-base titration, select a color-changing indicator based on the equivalence point pH
- Describe acid-base, redox, precipitation and complex-formation titrations
- Describe potentiometric, conductometric, amperometric and coulometric titration methods
- Identify when a back titration might be appropriate
- Describe how the titration method is chosen