Laboratory glassware refers to a variety of equipment, traditionally made of glass, used for scientific experiments and other work in science, especially in chemistry and biology laboratories. Glass in the common sense refers to a Hard, Brittle, transparent Solid, such as that used for Windows many In scientific inquiry an experiment ( Latin: Ex- periri, "to try out" is a method of investigating particular types of research questions or Science (from the Latin scientia, meaning " Knowledge " or "knowing" is the effort to discover, and increase human understanding Chemistry (from Egyptian kēme (chem meaning "earth") is the Science concerned with the composition structure and properties Foundations of modern biology There are five unifying principles A laboratory (informally lab) is a facility that provides controlled conditions in which scientific Research, Experiments and Some of the equipment is now made of plastic for cost, ruggedness, and convenience reasons, but glass is still used for some applications because it is relatively inert, transparent, more heat-resistant than some plastic up to a point, and relatively easy to customize. Plastic is the general common term for a wide range of synthetic or semisynthetic organic solid materials suitable for the manufacture of industrial products In English to be inert is to be in a state of doing little or nothing In Optics, transparency (also called pellucidity) is the Material property of allowing Borosilicate glasses—formerly called Pyrex—are often used because they are less subject to thermal stress. Borosilicate glass is a type of Glass with the main glass-forming constituents Silica and Boron oxide. Pyrex is a brand name for glassware introduced by Corning Incorporated in 1915 Stress is a measure of the average amount of Force exerted per unit Area. For some applications quartz is used for its ability to withstand high temperatures or its transparency in certain parts of the electromagnetic spectrum. Quartz (from German) is the most abundant Mineral in the Earth 's Continental crust (although Feldspar is more common in The electromagnetic (EM spectrum is the range of all possible Electromagnetic radiation frequencies In some applications, especially some storage bottles, darkened brown glass is used to keep out much of the outside light so that the effect of light on the contents inside is minimized. A bottle is a container with a neck that is narrower than the body and a "mouth Special-purpose materials are also used; for example, hydrofluoric acid is stored and used in polyethylene containers because it attacks glass. Hydrofluoric acid is a Solution of Hydrogen fluoride in Water. Polyethylene or polythene ( IUPAC name poly(ethene) is a Thermoplastic commodity heavily used in consumer products (notably the 
There are many different kinds of laboratory glassware items, the majority of which are covered in separate articles of their own; see the list further below. Such glassware is used for a wide variety of functions which include volumetric measuring, holding or storing chemicals or samples, mixing or preparing solutions or other mixtures, containing lab processes like chemical reactions, heating, cooling, distillation, separations including chromatography, synthesis, growing biological organisms, spectrophotometry, and containing a full or partial vacuum. A chemical substance is a Material with a definite chemical composition. In Chemistry, a solution is a Homogeneous Mixture composed of two or more substances A chemical reaction is a process that always results in the interconversion of Chemical substances The substance or substances initially involved in a chemical reaction are called Distillation is a method of separating Mixtures based on differences in their volatilities in a boiling liquid mixture This vacuum means "absence of matter" or "an empty area or space" for the cleaning appliance see Vacuum cleaner. When in use, laboratory glassware is often held in place with clamps made for that purpose, which are likewise attached and held in place by stands or racks. This article covers aspects of laboratory glassware which may be common to several kinds of glassware and may briefly describe a few glassware items not covered in other articles.
Most laboratory glassware is now mass-produced, but many large laboratories employ a glass blower to construct specialized pieces. Mass production (also called flow production, repetitive flow production, series production, or serial production) is the production of Glassblowing is a glassforming technique that involves inflating the molten glass into a bubble or parison with the aid of the blowpipe or blow tube This construction forms a specialized field of glassblowing requiring precise control of shape and dimension. In addition to repairing expensive or difficult-to-replace glassware, scientific glassblowing commonly involves fusing together various glass parts—such as glass joints and tubing, stopcocks, transition pieces, and/or other glassware or parts of them to form items of glassware, such as vacuum manifolds, special reaction flasks, etc. Glass tubes or glass tubing are hollow pieces of Borosilicate glass used in Laboratory glassware. In Quantum field theory, the Vacuum state may be Degenerate. Each pure vacuum state generates its own Superselection sector. A chemical reaction is a process that always results in the interconversion of Chemical substances The substance or substances initially involved in a chemical reaction are called Laboratory flasks are vessels (containers which fall into the category of Laboratory equipment known as glassware.
Various types of joints and stopcocks are available separately and come fused with a length of glass tubing, which a glassblower may use to fuse to another piece of glassware. Glass tubes or glass tubing are hollow pieces of Borosilicate glass used in Laboratory glassware.
A thin layer of grease is usually applied to the ground-glass surfaces to be connected, and the inner joint is inserted into the outer joint such that the ground-glass surfaces of each are next to each other to make the connection. Although the word grease originally described the rendered fat of animals the term is now applied more broadly to mean a Lubricant of higher initial Viscosity The use of grease helps to provide a good seal and prevents the joint from seizing, allowing the parts to be disassembled easily. 
PTFE (Teflon) sleeves and PTFE sealing rings have been used in between joints to fit them together instead of grease. In Chemistry, poly(tetrafluoroethene or poly(tetrafluoroethylene ( PTFE) is a synthetic Fluoropolymer which finds numerous applications In Chemistry, poly(tetrafluoroethene or poly(tetrafluoroethylene ( PTFE) is a synthetic Fluoropolymer which finds numerous applications 
In a lab experiment or process—such as a distillation or a reflux—ground glass joints make it possible to rapidly assemble the set-up from component glassware items in a leak-tight but non-permanent way. Ground_glass_joint_closedjpg|right|thumb|The same joint closed Distillation is a method of separating Mixtures based on differences in their volatilities in a boiling liquid mixture This article is about using reflux in chemical engineering and chemistry Using old technology, this was often done with rubber (or possibly cork) stoppers inserted between the component glassware items. Holes could be made in such stoppers to insert glass tubes or the ends of some glass items. However, rubber (and of course cork) are not as chemically inert or heat-resistant as glass and degrade with age. In order to connect the hollow inner spaces of the glassware components, these types of joints are hollow on the inside and open at the ends, except for stoppers.
Two general types of ground glass joints are fairly commonly used: joints that are slightly conically-tapered and ball and socket joints (sometimes called spherical joints).
Conically tapered ground glass joints consist of a male and a female half which are manufactured to a standard 1:10 taper. Apart from stoppers, most conically tapered joints are hollow to allow liquids or gases to flow through. An example of the use of conically-tapered joints is to join a round bottom flask, Liebig condenser, and oil bubbler together to allow a reaction mixture to be refluxed. Round-bottom flasks (also called round-bottomed flasks and Erlenmeyer Bulbs) are types of Flasks having spherical bottoms used as Laboratory glassware In a Laboratory, a condenser is a piece of Laboratory glassware used to cool hot vapors or liquids An oil bubbler is a piece of Laboratory glassware which consists of a glass bulb filled with a small amount of Silicone oil. This article is about using reflux in chemical engineering and chemistry
Here, the inner joint is a ball and the outer joint is a socket, both having holes leading to the interior of their respective tube ends to which they are fused. Ball and socket joints are used where some degree of free-play is necessary, such as when joining a cold trap to a gas manifold for a Schlenk line. In Vacuum applications a cold trap is a device that condenses all Vapors except the permanent gases into a liquid or solid The Schlenk line (also vacuum gas manifold is a commonly-used piece of Chemistry apparatus developed by Wilhelm Schlenk. 
For either standard taper joints or ball-and-socket joints, inner and outer joints with the same numbers are made to fit together. When the joint sizes are different, ground glass adapters may be available (or made) to place in between to connect them. Special clips or pinch clamps, known as Keck clips, may be placed around the union of the joints to help keep them together. Ground_glass_joint_closedjpg|right|thumb|The same joint closed
There are also glass joints available sometimes which use an O-ring between them to form a leak-tight seal. An o-ring, also known as a packing or a toric joint, is a mechanical Gasket in the shape of a Torus; it is a loop of Elastomer with  Such joints are more symmetrical in theory with a tubular joint on each side having a widened tip with a concentric circular groove into which an elastomer O-ring can be inserted between the two joints. An elastomer is a Polymer with the property of Elasticity. The term which is derived from elastic polymer, is often used interchangeably with the term O-ring joints are sized based on the inner diameter in mm of the joint. Since they can come apart rather easily, a clip or pinch clamp is needed to hold them together. The elastomer of the O-ring is more limited in high temperature resistance than other types of glass joints using high temperature grease. Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature
Round slightly spiral threaded connections are possible on tubular ends of glass items. Such glass threading can face the inside or the outside. In use, glass threading is screwed into or onto non-glass threaded material such as plastic. Glass vials typically have outer threaded glass openings onto which caps can be screwed on. Bottles and jars in which chemicals are sold, transported, and stored usually have threaded openings facing the outside and matching non-glass caps or lids.
Occasionally, it may be desired to fuse a glassware item to a metal item with a tubular pathway between them. The M acro E xpansion T emplate A ttribute L anguage complements TAL, providing macros which allow the reuse of code across This requires the use of a glass-to-metal transition joint. Most glass used in laboratory glassware does not have the same coefficient of thermal expansion as metal, so fusing the usual type of glass with metal is likely to result in cracking of the glass. When the Temperature of a substance changes the energy that is stored in the Intermolecular bonds between atoms changes These special transition joints have several short sections of special types of glass fused together between the metal and the usual type of glass, each having more gradual changes in thermal expansion coefficients.
Laboratory glassware, such as Buchner flasks and Liebig condensers, may have tubular glass tips serving as hose connectors with several ridged hose barbs around the diameter near the tip. A Büchner flask, also known as a vacuum flask, filter flask side-arm flask or Kitasato flask, is a thick-walled Erlenmeyer flask with a short glass In a Laboratory, a condenser is a piece of Laboratory glassware used to cool hot vapors or liquids This is so that the tips can have the end of a rubber or plastic tube mounted over them to connect the glassware to another system such as a vacuum, water supply, or drain. A special clip may be placed over the end of the flexible tube surrounding the connector tip to prevent the hose from slipping off the con
Describing glassware can be complicated since manufactures provide conflicting names for glassware. For example ChemGlass calls a glass stopcock what Kontes calls a glass plug. Despite this it is clear there are two main types of valves used in laboratory glassware, the stopcock valve and the threaded plug valve. These and other terms used below are defined in detail since they are bound to conflict with different sources.
Stopcocks are often parts of laboratory glassware such as burettes, separatory funnels, Schlenk flasks, and columns used for column chromatography. A burette (also buret) is a vertical cylindrical piece of Laboratory glassware with a volumetric graduation on its full length and a precision tap or Stopcock A Schlenk flask, or Schlenk tube is a reaction vessel typically used in Air sensitive chemistry invented by Wilhelm Schlenk. Chromatography (from Greek χρώμα chroma, color and γραφειν"graphein" to write is the collective term for a family of Laboratory The stopcock is a smooth tampered plug or rotor with a handle, which fits into a corresponding ground glass female joint. The stationary female joint is designed such that it joins two or more pieces of glass tubing. The stopcock has holes bored through it which allow the tubes attached to the female joint to be connected or separated with partial turns of the stopcock. Most stopcocks are solid pieces with linear bores although some are hollow with holes to simple holes that can line up the joints tubing. The stopcock is held together with the female joint with a metal spring, plastic plug retainer, a washer and nut system, or in some cases vacuum. Stopcocks plugs are generally made out of ground glass or an inert plastic like PTFE. The ground glass stopcocks are greased to create an airtight seal and prevent the glass from fusing. The plastic stopcocks are at most lightly oiled.
Stopcocks are generally available individually with some length of glass tubing at the ports so that they can be joined by a glass blower into custom apparatus at the point of use. This is especially common for the large glass manifolds used in high vacuum lines.
The more examples are featured in the gallery. This is a small sampling of stopcock valves many additional variation exist in both plug boring and joint assembly.
Threaded plug valves are used significantly in air-sensitive chemistry as well as when a vessel must be closed completely as in the case of Schlenk bombs. A Schlenk flask, or Schlenk tube is a reaction vessel typically used in Air sensitive chemistry invented by Wilhelm Schlenk. The construction of a threaded plug valve involves a plug with a threaded cap which are made so that they fit with the threading on a corresponding pieces of female glass. Screwing the plug in part way first engages one or more o-rings, made of rubber or plastic, near the plugs base which seals the female joint off from the outer atmosphere. Screwing the plug valve all the way in engages the plugs tip with a beveled constriction in the glass which provides a second seal. This seal separates the region beyond the bevel and the o-rings already mentioned.
With solid plugs a tube or area exists above and below the bevel and turning the plug controls access. In a number of cases its convent to fully remove a plug which can give access to the region beyond the bevel. Plugs are generally made of an inert plastic such as PTFE with and are attached to a threaded sleeve in such a way that the sleeve can been turned without spinning the plug. The contact with the bevel is made by an o-ring fitted to the tip of the plug or by the plug itself. There are a few examples where the plug in made of glass. In the case of glass plugs the joint contact is always a rubber o-ring but are still prone to shattering.
Not all plugs are solid. Some plugs are bored with a T-junction. In these systems the plug extends beyond the threaded sleeve and is designed to form an airtight fitting with glass tubing or hosing. The shaft of the plug is bored from beyond the threaded sleeve to a T-junction just before the bevel plug contact. When the plug is fully sealed region beyond the bevel is separated from the plug shaft as well as the bore which leads out of its shaft. When the plug bevel contact is released the two regions are exposed to each other. These valves have also be used as a grease free alternative to straight bored stopcocks common to Schlenk flasks. A Schlenk flask, or Schlenk tube is a reaction vessel typically used in Air sensitive chemistry invented by Wilhelm Schlenk. The high symmetry and concise design of these valves has also made them popular for capping NMR tubes. Such NMR tubes can be heated without the loss of solvent thanks to the valves gas tight seal. NMR tubes with T-bore plugs are widely known as J. Young NMR tubes named after the brand name of valves most commonly used for this purpose. An couple images of J. Young NMR tubes and a J. Young NMR tube adapter are in the gallery.
Fritted glass is finely porous glass through which gas or liquid may pass. It is made by sintering together glass particles into a solid but porous body.  This porous glass body can be called a frit. Applications in laboratory glassware include use in fritted glass filter items, scrubbers, or spargers. In Chemistry and common usage a filter is a device (usually a membrane or layer that is designed Other laboratory applications of fritted glass include packing in chromatography columns and resin beds for special chemical synthesis.
In a fritted glass filter, a disc or pane of fritted glass is used to filter out solid particles, precipitate, or residue from a fluid, similar to a piece of filter paper. The fluid can go through the pores in the fritted glass, but the frit will often stop a solid from going through. A fritted filter is often part of a glassware item, so fritted glass funnels and fritted glass crucibles are available. 
Laboratory scale spargers, scrubbers, and gas-washing bottles are similar glassware items which may use a fritted glass piece fused to the tip of a gas-inlet tube. This article is about the pollution control device for other uses see Scrubber (disambiguation. This fritted glass tip is placed inside the vessel with liquid inside during use such that the fritted tip is submerged in the liquid. To maximize surface area contact of the gas to the liquid, a gas stream is slowly blown into the vessel through the fritted glass tip so that it breaks up the gas into many tiny bubbles. The purpose of sparging is to saturate the enclosed liquid with the gas, often to displace another gaseous component. In Chemistry, sparging is a technique which involves bubbling a chemically inert gas such as Nitrogen, Argon, or Helium, through a liquid The purpose of a scrubber or gas-washing bottle is to scrub the gas such that the liquid absorbs one (or more) of the gaseous components to remove it from the gas stream, effectively purifying the gas stream. This article is about the pollution control device for other uses see Scrubber (disambiguation.
If the glassware are still dirty, more caustic methods may be needed. Sonication is the act of applying sound (usually Ultrasound) energy to agitate particles in a sample for various purposes This includes soaking the piece in a saturated solution of sodium or potassium hydroxide in an alcohol ("base bath"), followed by a dilute solution of hydrochloric acid ("acid bath") to neutralize the excess base. Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature Potassium hydroxide is the Inorganic compound with the formula K[[hydroxide OH]] Hydrochloric acid is the Solution of Hydrogen chloride ( H[[Chlorine Cl]] in water Sodium hydroxide cleans glass by dissolving a tiny layer of silica, to give soluble silicates. For the Artificial intelligence Androids of the 1990s Science fiction series Space Above and Beyond, see Silicate (AI
Older methods involving aqua regia (for removing metals from frits), piranha solution and chromic acid (for removing organics) are generally considered unsafe because of possible explosions and the corrosive/toxic materials involved. Aqua regia ( Latin for royal water) is a highly corrosive fuming yellow or red solution Piranha solution, also known as piranha etch, is a mixture of Sulfuric acid (H2SO4 and Hydrogen peroxide (H2O2 Chromic acid generally refers to a collection of compounds generated by the acidification of solutions containing Chromate and Dichromate anions or the
A straight bore plastic stopcock with sans female joint. Note its washer and nut system for attaching to its female joint.
A T-bore glass stopcock in a three way assembly. Two of the outlets end in plain hose adapters while the third ends in a male 14/20 ground glass joint. This stopcock is attached with an easily removed metal spring.
A double oblique bore glass three-way stopcock.
A single hole hollow glass stopcock held in place by vacuum.
A J. Young NMR tube attached to an adapter with a female 24/40 joint already greased. Note the hole resulting from the T-bore in the side of the PTFE plug.
A J. Young NMR tube from above looking down the hole that leads to the T-bore.
A Taper Joint Stopper with PTFE Sealing Ring. Optical transparency of the narrow sealing ring pressured by glass joint (right).