A volumetric flask is a specialized instrument used in the laboratory for precise solution preparation. Its core function is to control the liquid volume through a circular mark on the neck, ensuring that the nominal volume is achieved at a specific temperature (usually 20°C). Here is a detailed analysis synthesized from various sources:--

. Basic Structure and Definition1. Appearance characteristics- Pear-shaped flat bottom: easy to shake, mix, and clean, reducing residue.- Slender neck: reduces the liquid surface area, thereby minimizing reading errors.- Ground glass stopper: Ensure leak-tightness (test for leaks before use).- Annular marking: A single annular scale is engraved on the neck, and the lowest point of the concave liquid surface must be tangent to the marking to accurately determine the volume.---II. Material types and characteristics1. Glass volumetric flask- High borosilicate glass: resistant to high temperatures and thermal shock (such as 3.3 high borosilicate glass), can be directly heated (with asbestos mesh as a pad), suitable for the preparation of conventional acid and alkali solutions.- Accuracy level: Level A (high accuracy) with error ≤±0.05%, Level B with error ≤±0.1%.