Materials:
- Analytical balance
- Volumetric flask (1000 mL)
- Sodium hydroxide (NaOH) pellets or flakes
- Distilled or deionized water
Procedure:
1. Calculate the amount of NaOH needed:
Mass of NaOH = (Concentration in ppm) * (Volume of solution in liters) / (Molar mass of NaOH)
The molar mass of NaOH is approximately 40 g/mol.
In this case, we want to prepare 1000 mL (1 L) of a 10 ppm NaOH solution:
Mass of NaOH = (10 ppm) * (1 L) / (40 g/mol)
Mass of NaOH = 0.000025 g
2. Weigh out the required amount of NaOH using an analytical balance and transfer it to a clean and dry 1000 mL volumetric flask.
3. Add a small amount of distilled or deionized water to the flask and swirl gently to dissolve the NaOH.
4. Once the NaOH is completely dissolved, fill the volumetric flask up to the 1000 mL mark with distilled or deionized water.
5. Mix the solution thoroughly by inverting the flask several times or using a magnetic stirrer.
Note:
- This solution is very dilute and may not be suitable for all applications. For more concentrated solutions, adjust the amount of NaOH accordingly.
- Always wear appropriate safety gear, including gloves and eye protection, when handling NaOH.
- Store the prepared solution in a labeled, airtight container to prevent contamination.
