======Using Volumetric Flasks======


<WRAP right box>
**Materials: **{{$demo.materials_description}}\\
**Difficulty: **{{$demo.difficulty_description}}\\
**Safety: **{{$demo.safety_description}}\\
\\
**Categories:** {{$demo.categories}}
\\


**Alternative titles:** Preparing Dilutions with Volumetric Flasks
</WRAP>

====Summary====                   
{{$demo.summary}}



====Procedure====  
  - Calculate the required volume of stock solution needed.
    (stock volume × stock concentration = final volume × final concentration).  
  - Pipet the calculated volume of stock solution into a clean volumetric flask.  
  - Fill with distilled or lab-grade water until the liquid level is just below the graduation line.  
  - Stopper and mix thoroughly, then allow to return to room temperature if needed.  
  - Using a dropper, carefully add water until the bottom of the meniscus rests on the line.  
  - Mix again and transfer the final solution to a labeled storage container.



====Links==== 
How to use volumetric flasks - ISU Gen Chem Lab Tutorials: 
{{youtube>ttnR_YuYGC4?}}\\

How To Use a Volumetric Flask - FlinnScientific: 
{{youtube>hrvXuX0Ow3s?}}\\

📄 Volumetric Flasks - DEQ: [[https://cdn.ymaws.com/www.vwea.org/resource/collection/703D4FAA-351D-4D3A-8EC2-A2198D276DA7/BLS-5_VM_Volumetric_Flasks_2019.pdf]]\\

====Variations====
  * Prepare serial dilutions (10×, 100×, 1000×) by successively diluting a previous solution.  
  * Use different flask sizes (25 mL to 1000 mL) depending on the volume of solution required.  
  * Substitute plastic volumetric flasks with caps for fieldwork where breakage is a risk.  




====Safety Precautions====
  * Use lab-grade water appropriate to the test (e.g., ammonia-free water for nitrogen tests).  
  * Ensure volumetric flasks are clean and dry before use to avoid contamination.  
  * Handle glass flasks carefully to avoid breakage and cuts.  
  * Label all prepared solutions clearly to prevent mix-ups.




====Questions to Consider====
  * Why do volumetric flasks have only one graduation line? (To ensure maximum accuracy at a single calibrated volume.)
  * What is the difference between a stock solution and a standard solution? (Stock solution is concentrated; standard solution is the diluted form prepared for testing.)  
  * How does serial dilution differ from volumetric dilution? (Serial dilution uses stepwise dilutions, often by factors of 10; volumetric dilution prepares a single target concentration directly.)  
  * What errors might occur if the meniscus is not read at eye level? (Parallax error leads to inaccurate volume measurement.)