In: Chemistry
Why is it acceptable to use a clean, wet volumetric flask, instead of a clean, dry volumetric flask, when you are preparing your standard solutions by dilution? Explain in detail.
Ans. A standard volumetric flask has a single volume mark at its neck to represent the specified volume of the volume flask.
The solute is first added to a small volume (can be any volume) of distilled water taken in the volumetric flask and mixed well to solvate. The final volume is then made up to the mark with distilled water, and mixed well.
# Note that since volume is finally made up to the mark, the volume of water initially present in the volumetric flask does not affect the final volume. That is, if there were initially one drop or two drops or 10 drops or 100 drops or any other small volume of water in the clean, wet volumetric flask, the final volume in all cases would be made up to the mark- thus, the final volume remains unaffected of the initial amount of water present in it.
Therefore, it’s accepted to use clean, wet volumetric flasks instead of using a clean, dry flask as long as water is used to prepare the standard solution.