Use a volumetric flask to create a solution of known concentration and of a fixed, accurate volume (indicated by the mark).  Place a funnel on the flask and pour the required amount of solid into the funnel.  Dissolve the solid completely with enough water (this should be less than the amount required to fill the flask to the mark).



To further dilute the solution, carefully add more water to the flask until a centimeter below the mark.  At eye level, add the water drop-by-drop until the bottom of the meniscus lines up with the mark. 

Make sure that there are no drops of water hanging on to the flask above the mark when making this measurement.


Bottom of Mensicus


Place the cap on the volumetric flask.  Thoroughly mix the solution by shaking the flask while it is inverted.

Make sure the cap is tightly sealed to the flask during this process!