How do you make a 100 ppm solution of sodium chloride?

Materials required:

- Sodium chloride (NaCl)

- Deionized water

- Analytical balance

- Volumetric flask (1000 mL)

- Stir bar or magnetic stirrer

- Safety goggles and gloves

Procedure:

1. Calculate the amount of sodium chloride needed:

The concentration of a 100 ppm NaCl solution is 100 mg of NaCl per liter of solution. To make 1000 mL (1 L) of the solution, you need to calculate the mass of NaCl required:

Mass of NaCl = Concentration (ppm) x Volume of solution (L) / 1,000,000

Mass of NaCl = 100 ppm x 1 L / 1,000,000 = 0.1 g

2. Weigh the sodium chloride:

Using an analytical balance, accurately weigh 0.1 g of sodium chloride. Handle the sodium chloride carefully, wearing gloves and safety goggles.

3. Transfer the sodium chloride to a volumetric flask:

Transfer the weighed sodium chloride to a 1000 mL volumetric flask. Use a funnel to avoid spilling any solid.

4. Add deionized water:

Add a small amount of deionized water to the volumetric flask, enough to dissolve the sodium chloride. Swirl the flask gently to help dissolve the solid.

5. Stir the solution:

Use a magnetic stirrer or a stir bar to thoroughly mix the solution. Ensure all the sodium chloride is completely dissolved and there are no undissolved particles.

6. Fill the volumetric flask to the mark:

Using a graduated cylinder or a serological pipette, add deionized water to the volumetric flask until the bottom of the meniscus is exactly at the calibration mark. Be careful not to overfill the flask.

7. Mix the solution again:

Gently swirl the volumetric flask to ensure the solution is homogeneous.

8. Label the solution:

Affix a label to the volumetric flask indicating the concentration of the solution ("100 ppm NaCl solution") and the date it was prepared.

Your 100 ppm sodium chloride solution is now ready to use. Remember to wear gloves and safety goggles when handling chemicals and solutions.