NaOH, once its concentration has been validated through the use of a primary standard, is often used as a secondary standard. There are many examples of primary standards. We offer products with the tightest specifications in the industry to make your work easier. 448 West Fork Drive Primary standards are often used to make standard solutions, solutions with a precisely known concentration. Experience the RICCA difference. When KHP is used as a basimetric standard (e.g., in standardization of Perchloric Acid in Glacial Acetic Acid), Methyl Violet or Crystal Violet indicator is commonly used. Often, reagents are used to test for the presence or quantity of specific chemicals in a solution. To check the concentration of NaOH, a chemist must titrate a primary standard—in this case, a solution of potassium hydrogen phthalate (KHP). RICCA Chemical Company Also, a compound that might be a good primary standard for one purpose might not be the best choice for another analysis. You have plenty of things to worry about... inspections, deadlines, budgets... RICCA Chemical Company is the premier choice for all your chemical needs. Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. But in practice, this isn't always possible. A reagent is a chemical used to cause a chemical reaction with another substance. Potassium Hydrogen Phthalate (KHP) is a classic primary standard substance in that it is readily available in high purity; is relatively inexpensive; is easy to dry; is neither hygroscopic, oxidized by air, nor affected by Carbon Dioxide (thus making it easy to weigh out); does not undergo decomposition during storage; has a relatively high equivalent weight (thus reducing errors when weighed to 0.1 mg … A typical acidimetric reaction is: Phenolphthalein Indicator is most commonly used in titrations where KHP is used as an acidimetric standard to standardize solutions of bases. Arlington, TX 76012, E-Mail: customerservice@riccachemical.com. The most common include: A related term is secondary standard, a chemical that has been standardized against a primary standard for use in a specific analysis. Locate your product information quickly and efficiently. In chemistry, a primary standard is a reagent that is very pure, representative of the number of moles the substance contains, and easily weighed. It is also used in the quality control of Potassium Hydroxide and Sodium Hydroxide solutions, and in the standardization of Perchloric Acid in Glacial Acetic Acid. Standard Definition and Examples in Science, Chemistry Vocabulary Terms You Should Know, Make Ammonium Nitrate from Household Chemicals, Acids and Bases: Titration Example Problem, Definition and Examples of Acid-Base Indicator, How to Make Homemade Lye Using Two Ingredients, EDTA (ethylenediaminetetraacetic acid) solutions, Ph.D., Biomedical Sciences, University of Tennessee at Knoxville, B.A., Physics and Mathematics, Hastings College, Has a high equivalent weight (to reduce error from, Is not likely to absorb moisture from the air (, Zinc powder, which can be used to standardize, Potassium hydrogen phthalate, or KHP, which can be used to standardize perchloric acid and an aqueous base in an acetic. KHP is used in the manufacture of buffers, organic carbon standards, acidimetric standards and other products. The most common include: Sodium chloride (NaCl), which is used as a primary standard for silver nitrate (AgNO 3) reactions. We’ve delivered innovative products, uncompromising quality, and the tightest tolerances in the industry for over 45 years. There are many examples of primary standards. The reaction confirms that the solution is at a specific concentration. KHP does not absorb water or carbon dioxide, and it can provide visual confirmation that a 1-gram solution of NaOH really contains 1 gram. Secondary standards are commonly used to calibrate analytical methods. KHP does not absorb water or carbon dioxide, and it can provide visual confirmation that a 1-gram solution of NaOH really contains 1 gram. She has taught science courses at the high school, college, and graduate levels. It might seem odd that a reagent is needed to establish the concentration of a chemical in solution. In theory, it should be possible to simply divide the mass of the chemical by the volume of the solution. For example, sodium hydroxide (NaOH) tends to absorb moisture and carbon dioxide from the atmosphere, thus changing its concentration. A 1-gram sample of NaOH might not actually contain 1 gram of NaOH because additional water and carbon dioxide might have diluted the solution. Titration is a process in which small amounts of a reagent are added to a solution until a chemical reaction occurs. Primary standards are typically used in titration to determine an unknown concentration and in other analytical chemistry techniques. Potassium Hydrogen Phthalate (KHP) is a classic primary standard substance in that it is readily available in high purity; is relatively inexpensive; is easy to dry; is neither hygroscopic, oxidized by air, nor affected by Carbon Dioxide (thus making it easy to weigh out); does not undergo decomposition during storage; has a relatively high equivalent weight (thus reducing errors when weighed to 0.1 mg precision); is readily soluble in water; and is stoichiometric and instantaneous in reactions. Select the subject and enter the information below. With our robust quality system, extensive product line and custom capabilities, RICCA Chemical Company has everything you need! A good primary standard meets the following criteria: In practice, few chemicals used as primary standards meet all these criteria, although it's critical that a standard is of high purity. RICCA CHEMICAL COMPANY uses large quantities of KHP in the manufacture and quality control of its products.