Titrant vs. Titrand: Understanding the Difference

In chemistry, titration is a common laboratory technique used to determine the concentration of a substance in a solution. The process involves adding a known volume of a titrant, a solution with a known concentration, to a titrand, a solution with an unknown concentration, until the reaction is complete. The point at which the reaction is complete is known as the endpoint.

What is a Titrant?

The titrant is the solution that is added to the titrand in a titration experiment. It is typically a strong acid or base, and its concentration is known. The titrant is usually added to the titrand using a burette, which is a long, narrow tube with gradations that allow the volume of the titrant to be accurately measured.

What is a Titrand?

The titrand is the solution that is being analyzed in a titration experiment. Its concentration is unknown and is being determined through the use of the titrant. The titrand is typically an acid or base, but it could also be a salt or other compound that can be neutralized by the titrant.

Examples

Here are a few examples of titration experiments that illustrate the difference between the titrant and the titrand:

  • In a titration to determine the concentration of hydrochloric acid in a solution, the hydrochloric acid solution would be the titrand, and a sodium hydroxide solution would be the titrant.
  • In a titration to determine the concentration of a protein in a solution, the protein solution would be the titrand, and a solution of a known concentration of an amino acid would be the titrant.
  • In a titration to determine the concentration of a metal ion in a solution, the metal ion solution would be the titrand, and a solution of a known concentration of a ligand would be the titrant.

Difference between titrant and titrand

The key differences between the titrant and the titrand as as follows:

Concentration: The titrant has a known concentration, while the concentration of the titrand is unknown and is being determined through the use of the titrant.

Role in the experiment: The titrant is added to the titrand in a controlled manner, while the titrand is the solution being analyzed and its concentration is being determined.

Types of solutions: The titrant is typically a strong acid or base, while the titrand can be an acid, base, salt, or other compound that can be neutralized by the titrant.

Measuring volume: The volume of the titrant is usually measured using a burette, while the volume of the titrand is not typically measured.

Endpoint: The endpoint of a titration is the point at which the reaction between the titrant and the titrand is complete, and it is typically determined using an indicator or a pH meter.

Here is a summary of the differences between the titrant and the titrand in table format:

PropertyTitrantTitrand
ConcentrationKnownUnknown
Role in experimentSolution added to titrandSolution being analyzed
Types of solutionsStrong acid or baseAcid, base, salt, or other
Measuring volumeYes (using a burette)No
EndpointDetermined using indicator or pH meterN/A

In summary, the titrant is the solution with the known concentration that is added to the titrand, the solution with the unknown concentration, in a titration experiment. Understanding the difference between the titrant and the titrand is essential for correctly performing and interpreting the results of a titration experiment.