Brown volumetric flask

A brown volumetric flask is a pear shaped volumetric flask with a ground glass stopper and a marking on the neck, indicating that at the specified temperature, when the liquid concave surface is tangent to the marking on the neck of the volumetric flask, the volume of the solution is exactly equal to the volume marked on the flask. The volumetric flask is marked with temperature, capacity, and scale lines.

A volumetric flask is a precise instrument used to prepare a solution with an accurate concentration of a certain substance. It is a slender, pear shaped flat bottomed glass bottle with a ground glass stopper and a scale on the neck. When the volume inside the bottle reaches the marked line at the temperature, its volume is the indicated volume, which is generally a "volumetric flask" for measuring. But there are also two markings, with the upper one indicating the measured volume. There are various sizes of volumetric flasks that are often used in conjunction with pipettes, ranging from 5ml, 25ml, 50ml, 100ml to 250ml, 500ml, 1000ml, 2000ml, etc. It is mainly used for directly preparing standard solutions, accurately diluting solutions, and preparing sample solutions. The volumetric flask, also known as a volumetric flask, is generally made of high borosilicate material.