In titration analysis, what is added to the sample?

• A. A solvent.
• B. A standard solution.
• C. A catalyst.
• D. A buffer.

Answer: (B)

In titration, you determine an unknown concentration by reacting it with a solution of known concentration—the titrant. This standard solution is added gradually to the sample (the analyte) until the reaction reaches its endpoint, which lets you calculate the unknown amount using stoichiometry (C1V1 = C2V2). The solvent is just the medium, not the reagent being added to drive the reaction. A catalyst isn’t part of a typical titration, and a buffer may be used to control pH in some cases but isn’t the substance being added to perform the titration itself.