Schlenk-frit
A Schlenk-frit is a laboratory filtration device operating under inert gas conditions ( schlenk conditions). It separates air- and water-sensitive suspensions into liquid and solid parts. A Schlenk-frit is made of a glass tube with a ground glass joint at both ends, a fused filter (a porous glass disk) and valve A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fitting ...s at both sides. Use Before usage, the Schlenk-frit has to be heated, to remove water traces. The Schlenk-frit is put onto the product flask using an inert gas counterflow and closed at the top end with a second flask. The whole is turned 180° to start filtration. The liquid parts of the reaction mix go through the filter while the solid parts remain. To speed up the filtration pressure can be lowered at the bottom pa ...
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Air-free Technique
Air-free techniques refer to a range of manipulations in the chemistry laboratory for the handling of compounds that are air-sensitive. These techniques prevent the compounds from reacting with components of air, usually water and oxygen; less commonly carbon dioxide and nitrogen. A common theme among these techniques is the use of a fine (100–10−3 Torr) or high (10−3–10−6 Torr) vacuum to remove air, and the use of an inert gas: preferably argon, but often nitrogen. The two most common types of air-free technique involve the use of a glovebox and a Schlenk line, although some rigorous applications use a high-vacuum line. In both methods, glassware (often Schlenk tubes) are pre-dried in ovens prior to use. They may be flame-dried to remove adsorbed water. Prior to coming into an inert atmosphere, vessels are further dried by ''purge-and-refill'' — the vessel is subjected to a vacuum to remove gases and water, and then refilled with inert gas. This cycle is usually r ...
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Schlenk Frit
Schlenk can refer to: People * Wilhelm Schlenk (1879-1943), German chemist In chemistry * Schlenk flask * Schlenk line. or Schlenk apparatus * Schlenk equilibrium Other * Mepco Schlenk Engineering College MEPCO may refer to: * Mepco Schlenk Engineering College * Metal Powder Company * Multan Electric Power Company Multan Electric Power Company (MEPCO) ( ur, ), formerly known as Multan Power Supply Company, is an electric distribution company ...

Inert Gas
An inert gas is a gas that does not readily undergo chemical reactions with other chemical substances and therefore does not readily form chemical compounds. The noble gases often do not react with many substances and were historically referred to as the inert gases. Inert gases are used generally to avoid unwanted chemical reactions degrading a sample. These undesirable chemical reactions are often oxidation and hydrolysis reactions with the oxygen and moisture in air. The term ''inert gas'' is context-dependent because several of the noble gases can be made to react under certain conditions. Purified argon gas is the most commonly used inert gas due to its high natural abundance (78.3% N2, 1% Ar in air) and low relative cost. Unlike noble gases, an inert gas is not necessarily elemental and is often a compound gas. Like the noble gases, the tendency for non-reactivity is due to the valence, the outermost electron shell, being complete in all the inert gases. This is a tendency, ...
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Suspension (chemistry)
In chemistry, a suspension is a heterogeneous mixture of a fluid that contains solid particles sufficiently large for sedimentation. The particles may be visible to the naked eye, usually must be larger than one micrometer, and will eventually settle, although the mixture is only classified as a suspension when and while the particles have not settled out. Properties A suspension is a heterogeneous mixture in which the solute particles do not dissolve, but get suspended throughout the bulk of the solvent, left floating around freely in the medium. The internal phase (solid) is dispersed throughout the external phase (fluid) through mechanical agitation, with the use of certain excipients or suspending agents. An example of a suspension would be sand in water. The suspended particles are visible under a microscope and will settle over time if left undisturbed. This distinguishes a suspension from a colloid, in which the colloid particles are smaller and do not settle. Colloids a ...
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Ground Glass Joint
Ground glass joints are used in laboratories to quickly and easily fit leak-tight apparatus together from interchangeable commonly available parts. For example, a round bottom flask, Liebig condenser, and oil bubbler with ground glass joints may be rapidly fitted together to reflux a reaction mixture. This is a large improvement compared with older methods of custom-made glassware, which was time-consuming and expensive, or the use of less chemical resistant and heat resistant corks or rubber bungs and glass tubes as joints, which took time to prepare as well. One of the glassware items to be joined would have an ''inner'' (or male) ''joint'' with the ground glass surface facing outward and the other would have an ''outer'' (or female) ''joint'' of a correspondingly fitting taper with the ground glass surface facing inward. To connect the hollow inner spaces of the glassware components, ground glass joints are hollow on the inside and open at the ends, except for stoppers. His ...
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Valve
A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fittings, but are usually discussed as a separate category. In an open valve, fluid flows in a direction from higher pressure to lower pressure. The word is derived from the Latin ''valva'', the moving part of a door, in turn from ''volvere'', to turn, roll. The simplest, and very ancient, valve is simply a freely hinged flap which swings down to obstruct fluid (gas or liquid) flow in one direction, but is pushed up by the flow itself when the flow is moving in the opposite direction. This is called a check valve, as it prevents or "checks" the flow in one direction. Modern control valves may regulate pressure or flow downstream and operate on sophisticated automation systems. Valves have many uses, including controlling water for irrigation, ...
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Schlenk Frit Use
Schlenk can refer to: People * Wilhelm Schlenk (1879-1943), German chemist In chemistry * Schlenk flask * Schlenk line. or Schlenk apparatus * Schlenk equilibrium Other * Mepco Schlenk Engineering College MEPCO may refer to: * Mepco Schlenk Engineering College * Metal Powder Company * Multan Electric Power Company Multan Electric Power Company (MEPCO) ( ur, ), formerly known as Multan Power Supply Company, is an electric distribution company ...