primary standard

A primary standard is a highly pure substance used as a reference to measure and calibrate other chemicals or solutions accurately. Because of its purity and stability, it provides a reliable benchmark for determining the concentration of unknown solutions during experiments or quality control. Think of it as the “gold standard” in chemistry—someone with a well-known, precise value that helps ensure all measurements are accurate and consistent. Primary standards are essential for ensuring the accuracy of titrations, calibrations, and various analytical procedures.