In a laboratory, there are several primary standard solutions commonly used for analytical purposes. These solutions are highly purified and accurately prepared to have known concentrations of specific substances. Here are some examples of primary standard solutions:
- Sodium hydroxide (NaOH): Used for acid-base titrations and standardization of acid solutions.
- Potassium permanganate (KMnO₄): Frequently used as an oxidizing agent and for redox titrations.
- Sodium carbonate (Na₂CO₃): Utilized for acid-base titrations and standardization of acid solutions.
- Hydrochloric acid (HCl): Commonly used as a strong acid for neutralization reactions and standardization of base solutions.
- Sulfuric acid (H₂SO₄): A strong acid used for various purposes, including acid-base titrations and preparation of buffer solutions.
- Potassium iodate (KIO₃): Employed for iodometry and standardization of sodium thiosulfate solutions.
- EDTA (Ethylene-diamine-tetraacetic acid): Used as a chelating agent in complexometric titrations and for calcium and magnesium determinations.
- Ferrous ammonium sulfate (Fe(NH₄)₂(SO₄)₂): Utilized as a reducing agent and for redox titrations, such as the determination of hydrogen peroxide concentration.
These are just a few examples, and the specific primary standard solutions used in a laboratory can vary depending on the analytical techniques and experiments being performed.