Defining a Titrant
A titrant is a solution of a precisely known concentration that is added during a chemical titration to determine the concentration of another solution, known as the analyte or titrand. The titrant reacts with the analyte in a predictable and complete chemical reaction.
Section 2: The Role of the Titrant in Titration
In a titration experiment, the titrant is carefully dispensed from a burette into the analyte solution. The volume of titrant required to completely react with the analyte is measured. This point of complete reaction, called the equivalence point, allows for the calculation of the analyte's unknown concentration based on the known concentration and volume of the titrant used.
Section 3: A Practical Example
Consider determining the concentration of an unknown hydrochloric acid (HCl) solution. A solution of sodium hydroxide (NaOH) with a precisely known concentration, such as 0.100 M, would be used as the titrant. The NaOH titrant is slowly added to the HCl analyte until a pH indicator signals that the acid has been completely neutralized.
Section 4: Importance of the Titrant's Known Concentration
The accuracy of any titration is fundamentally dependent on the accuracy of the titrant's concentration. Because it serves as the reference for the entire measurement, the titrant is also called a 'standard solution.' Any error in its concentration will directly cause an error in the calculated concentration of the analyte.