What is the primary standard for the preparation of silver.
The primary standard for the preparation of silver is known as silver nitrate (AgNO3). Silver nitrate is widely used in analytical chemistry and is considered a primary standard because it is highly pure and its concentration can be accurately determined. To prepare silver nitrate, you will need the following materials and steps:
Materials:
- Silver metal (high purity)
- Nitric acid (HNO3)
- Distilled water
Steps:
1. Start by ensuring that you have all the necessary safety equipment, such as gloves and safety goggles, as both silver metal and nitric acid can be hazardous.
2. Weigh a specific amount of silver metal on an analytical balance. The exact amount will depend on the concentration of silver nitrate you wish to prepare.
3. In a fume hood or well-ventilated area, carefully add the weighed silver metal to a suitable container (e.g., glass beaker) and set it aside. It is crucial to handle the silver metal with caution to avoid accidental spills or contact.
4. In a separate container, measure the appropriate volume of concentrated nitric acid (HNO3). The volume of nitric acid required will depend on the stoichiometry of the reaction and the desired concentration of silver nitrate solution.
5. Slowly add the measured nitric acid to the container holding the silver metal. Take extreme care as the reaction between silver metal and nitric acid is exothermic and can release toxic nitrogen dioxide gas. It is important to carry out this step under proper ventilation.
6. Allow the reaction to occur until all the silver metal has dissolved completely. This process may take some time, depending on the amount of silver and the concentration of nitric acid used.
7. Once the silver metal has completely dissolved, add distilled water to the container in order to dilute the solution and bring it to the desired volume. The volume of water required will depend on the desired concentration of the silver nitrate solution.
8. Mix the solution thoroughly to ensure homogeneity.
9. Finally, the resulting solution is your prepared silver nitrate (AgNO3) solution, which can be used as a primary standard in various analytical techniques.
Remember to label your container appropriately and store the silver nitrate solution in a cool and dark place, as it is light-sensitive and can decompose over time.