How to Prepare 0.1 M NaOH Solution in 250 mL
Preparing a 0.1 M NaOH solution in 250 mL is a common task in laboratory settings. Sodium hydroxide, also known as caustic soda, is a strong base that is widely used in various applications, including chemical synthesis, cleaning, and water treatment. To ensure accurate and safe preparation, follow these step-by-step instructions.
Materials Needed:
1. 0.1 M NaOH pellets or powder
2. Distilled water
3. A 250 mL volumetric flask
4. A graduated cylinder or a measuring pipette
5. A magnetic stirrer (optional)
6. Safety equipment: gloves, goggles, and a lab coat
Step 1: Weigh the NaOH Pellets or Powder
Start by weighing the appropriate amount of NaOH pellets or powder. To prepare a 0.1 M solution, you need 0.1 moles of NaOH. The molar mass of NaOH is approximately 40.00 g/mol. Therefore, you will need 4.00 g of NaOH for a 250 mL solution.
Step 2: Transfer the NaOH to the Volumetric Flask
Using a clean, dry spoon, transfer the weighed NaOH into the 250 mL volumetric flask. Be cautious as NaOH can cause skin and eye irritation.
Step 3: Add a Small Amount of Distilled Water
Add a small amount of distilled water to the flask, ensuring that the NaOH is fully dissolved. Stir the solution gently using a magnetic stirrer or a glass rod.
Step 4: Fill the Flask to the Mark
Once the NaOH is completely dissolved, use a graduated cylinder or a measuring pipette to add distilled water to the flask. Fill the flask to the mark, leaving about 1-2 cm of space at the top.
Step 5: Cap and Swirl the Flask
Secure the flask’s cap and swirl it gently to mix the solution thoroughly. Ensure that the solution is homogenous and that there are no undissolved particles.
Step 6: Final Adjustments
Check the solution’s volume by placing the flask on a level surface. If the solution’s meniscus is below the mark, add a small amount of distilled water and swirl the flask again. Repeat this process until the meniscus aligns with the mark.
Step 7: Safety Precautions
Handle NaOH with care, as it can cause severe burns. Always wear gloves, goggles, and a lab coat when working with this chemical. Store the prepared solution in a labeled, tightly sealed container away from heat and direct sunlight.
Conclusion
Preparing a 0.1 M NaOH solution in 250 mL is a straightforward process, but it requires attention to detail and safety precautions. By following these steps, you can ensure accurate and safe preparation of this important chemical for your laboratory needs.
