Primary Standard
What is Primary Standard?
A primary standard is a highly pure, stable substance with known composition that is used to prepare standard solutions of accurately known concentration (for calibration in titrations). A primary standard must have high purity, be stable in air, have a high molar mass (to reduce weighing errors), and react completely and stoichiometrically with the analyte. Potassium hydrogen phthalate (KHP) is a common primary standard for acid–base titrations.
Key Facts
Frequently Asked Questions
A primary standard is a highly pure, stable substance with known composition that is used to prepare standard solutions of accurately known concentration (for calibration in titrations). A primary standard must have high purity, be stable in air, have a high molar mass (to reduce weighing errors), and react completely and stoichiometrically with the analyte. Potassium hydrogen phthalate (KHP) is a common primary standard for acid–base titrations.