Volumetric flask in the context of Calibration

Laboratory glassware is a variety of equipment used in scientific work, traditionally made of glass. Glass may be blown, bent, cut, molded, or formed into many sizes and shapes. It is commonly used in chemistry, biology, and analytical laboratories. Many laboratories have training programs to demonstrate how glassware is used and to alert first–time users to the safety hazards involved with using glassware.

Laboratory flasks are vessels or containers that fall into the category of laboratory equipment known as glassware. In laboratory and other scientific settings, they are usually referred to simply as flasks. Flasks come in a number of shapes and a wide range of sizes, but a common distinguishing aspect in their shapes is a wider vessel "body" and one (or sometimes more) narrower tubular sections at the top called necks which have an opening at the top. Laboratory flask sizes are specified by the volume they can hold, typically in SI units such as milliliters (mL or ml) or liters (L or l). Laboratory flasks have traditionally been made of glass, but can also be made of plastic.

At the opening(s) at top of the neck of some glass flasks such as round-bottom flasks, retorts, or sometimes volumetric flasks, there are outer (or female) tapered (conical) ground glass joints. Some flasks, especially volumetric flasks, come with a laboratory rubber stopper, bung, or cap for capping the opening at the top of the neck. Such stoppers can be made of glass or plastic. Glass stoppers typically have a matching tapered inner (or male) ground glass joint surface, but often only of stopper quality. Flasks which do not come with such stoppers or caps included may be capped with a rubber bung or cork stopper.

In analytical chemistry, a standard solution (titrant or titrator) is a solution containing an accurately known concentration. Standard solutions are generally prepared by dissolving a solute of known mass into a solvent to a precise volume, or by diluting a solution of known concentration with more solvent. A standard solution ideally has a high degree of purity and is stable enough that the concentration can be accurately measured after a long shelf time.

Making a standard solution requires great attention to detail to avoid introducing any risk of contamination that could diminish the accuracy of the concentration. For this reason, glassware with a high degree of precision such as a volumetric flask, volumetric pipette, micropipettes, and automatic pipettes are used in the preparation steps. The solvent used must also be pure and readily able to dissolve the solute into a homogenous solution.