The weighing of the pure water conical flask with stopper and bottle mouth why to avoid friction with the answer
Avoid grinding mouth and bottle stopper on the water leaking out or evaporate in a process. Change the strength of the water.
To avoid leakage or evaporation of water from the mouth and bottle, or in the weighing, the water on the mouth and bottle also occupies part of the volume, so that the volume of the final water has changed and the weighing is inaccurate.
