What is the difference between a calibrated and an uncalibrated volumetric flask?

Answer 1

The difference is, a worthwhile piece of glassware versus a nice vase. Volumetric flasks are unlike many other types of commonly used scientific glassware in that their only purpose is to be an incredibly accurate measuring device for liquids. They are not used for mixing, heating, stirring or any of the other common applications for other flasks. They have a single measurement line, and when filled and read properly (by the bottom of the fluid meniscus on the line) contain exactly however many milliliters of fluid indicated. This accuracy requirement is why they are among the most expensive pieces of glassware to purchase; by their very nature they must be calibrated in order to be of any worth. The larger the volume, the greater the cost. They should be scrupulously cleaned with proper detergents and high quality distilled water, and kept protected from dusts and other contaminants. Most often, their use is limited to analytical chemistry or similar applications requiring extreme precision of measurement. So given that their purpose is to measure, to have one be "uncalibrated" would be ridiculous. If a person wanted to measure fluid with less accuracy, there are a number of common graduated cylinders that would be used instead.