Guide: 1. The volumetric flask is a measuring instrument. If the reagent or standard substance (especially corrosive, strong acid, strong alkali, etc.) is assembled for a long time, the volume of the volumetric flask may be inaccurate...

1. The volumetric flask is a measuring instrument. If the reagent or standard substance (especially corrosive, strong acid, strong alkali, etc.) is assembled for a long time, the volume of the volumetric flask may be inaccurate.

2. The volumetric flask needs to be shaken after the volume is fixed, and most volumetric flasks should be upside down according to regulations. Therefore, using a volumetric flask to hold the preparation reagent or standard substance for a long time may affect the sealing performance of the bottle stopper; thereby causing leakage, loss, etc. during the preparation and shaking process.

3. For regular reagent bottles, especially standard substances, the caps are screwed on in most cases; according to most reagent bottles are brown or colored reagent bottles. Due to long-term storage, special reagents may be decomposed when exposed to light.