A laboratory volumetric flasks is a type of laboratory glassware with a precise volume, commonly used for preparing standard solutions and diluting chemicals accurately. It has a pear-shaped or flat-bottomed body with a long, narrow neck marked with a single calibration line to indicate a specific volume (e.g., 50 mL, 100 mL, 500 mL). This calibration ensures high accuracy in measurements, as the flask can hold an exact volume when filled to this line. Laboratory volumetric flasks are typically made from borosilicate glass or plastic, resistant to chemicals and thermal stress. They often come with a stopper to prevent contamination or evaporation of the contents, making them essential for precise quantitative analysis in laboratories.