Science, Tech, Math › Science Volumetric Flask Definition in Chemistry What You Need to Know About Volumetric Flasks Share Flipboard Email Print Volumetric flasks are used to accurately prepare solutions for chemistry. TRBfoto/Getty Images Science Chemistry Chemical Laws Basics Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated August 04, 2018 A volumetric flask is a type of laboratory glassware used to prepare solutions. A volumetric flask is a flat bottomed bulb with a elongated neck calibrated to hold a set volume at a mark on the neck. The flask may also be called a graduated flask or measuring flask because its mark specifies a precise volume measurement. The mark on the flask neck indicates the volume contained. When emptied, some portion of liquid may remain in the container, so the mark (unlike for a pipette) does not indicate the amount to be dispensed. It should be noted volumetric flasks are calibrated for a particular temperature (usually 20 °C), which is indicated on the label. Most volumetric flasks are either transparent glass or plastic, although some flasks are amber-colored for the preparation of light-sensitive solutions. The mouth of the flask may have either a joint to accommodate a stopper or a screw cap. Volumetric Flask Standards All volumetric flasks are not created equal! There are higher and lower precision flasks. A volumetric flask made to conform to a high standard is a Class A or Class 1 flask. Its tolerance, temperature, precision, and volume will be indicated on the glassware. A Class B flask does not conform to as high a standard and may not include all of this information. Class A flasks are used for analytical chemistry work, while Class B flasks are suitable for most educational and qualitative work.