titrant
/ TY-trunt /
Think of the lemon juice you dribble into the soup — the liquid you are adding, drop by drop, whose strength you already know. In a titration that controlled liquid has a name: the titrant.
The titrant is the reagent solution of known, accurately fixed concentration that you deliver from a burette into the sample. As it flows in, it reacts with the substance being measured; the volume of titrant needed to reach completion is the number you ultimately use in the calculation.
The titrant matters because the whole result rides on knowing its concentration precisely — a titrant whose strength is only roughly known gives only a roughly known answer. That is why titrants are usually standardized against a reliable reference before use, and stored carefully so their concentration does not drift.
When acetic acid in vinegar is measured, the standardized sodium hydroxide solution delivered from the burette is the titrant, while the vinegar in the flask is the analyte being measured.
The titrant is the known solution you add; the analyte is what you measure.
A titrant is almost always a standard solution, but the two words differ in emphasis: standard solution stresses the known concentration, while titrant stresses its role as the liquid being added in the titration.