Buchner flasks funnels

Apparatus for recrystallization, Erlenmeyer flask, Buchner flask, funnel, and water aspirator... 

Apparatus for filtration, Erlenmeyerflasks, Buchner flasks, funnel, fast flow filter paper, and water aspirator. 

This type of filtration is almost invariably performed with the aid of a Buchner flask and funnel, by means of which a rapid and almost complete separation can be obtained. The Buchner flask A (Fig. 4) consists of a simple thick-walled conical flask with a short side-arm for connection to a water-pump. Into the neck of the flask is fitted the Buchner funnel B which consists usually of a cylindrical porcelain funnel, the bed of which is pierced by a... 

The technique of the filtration of hot solutions has already been described in Section 11,28. The filtration of cold solutions will now be considered this operation is usually carried out when it is desired to separate a crystalline solid from the mother liquor in which it is suspended. When substantial quantities of a solid are to be handled, a Buchner funnel of convenient size is employed. The ordinary Buchner fimnel (Fig. 11,1, 7, a) consists of a cylindrical porcelain funnel carrying a fixed, flat, perforated porcelain plate. It is fitted by means of a rubber stopper or a good cork into the neck of a thick-walled filtering flask (also termed filter flask, Buchner flask or suction flask) (Fig. 11,1, 7, c), which is connected by means of thick-walled rubber tubing (rubber pressure tubing) to a similar flask or safety bottle, and the latter is attached by rubber pressure tubing to a filter pump the safety bottle or trap is essential since a sudden fall in water pressure may result in the water sucking back. The use of suction renders rapid filtration possihle... 

M sodium hydroxide solution terf-butylmethylether (TBME, 100 mL) anhydrous magnesium sulfate two 100 mL round-bottomed flasks two magnetic stirring hotplates one Buchner flask, 100 mL one Buchner funnel one 100 mL separating funnel rotary evaporator. 

Remove both the Suba-Seal and polythene cap and place the filter tube in the rubber cone adapter (42 x 27 mm) used with the adapter funnel attached to the Buchner flask, or other suitable device. Wash any particles from the polythene cap into the filter tube, apply just sufficient suction to remove the gamanase-cellulase solution, then wash the residual undigested fibre with hot distilled water (approximately 80°C). Finally wash well with acetone, leave to air dry in a fume cupboard, and when no smell of acetone can be detected, dry in an oven overnight at 100°C ( 2°C). Cool in a desiccator and weigh the filter tube plus residue. 

Magnetic stirrer plate 200 mL separating funnel Two 200 mL Erlenmeyer flasks Buchner funnel, diameter 4 cm 250 mL Buchner flask Filter paper... 

Dry ice-acetone bath Two Buchner funnels, diameter 2 cm Two lOOmL Buchner flasks Filter paper... 

Hydrogen pressure autoclave, 15mL One glass sintered funnel One Buchner flask, 50 mL... 

One 100 ml round bottom flask with stirrer bar One glass sintered funnel, diameter 7 cm One Buchner flask, 250 mL... 

Dissolve 30 grms. of potassium chlorate in 60 c.c. of warm water contained in a 250 c.c. flask. Add 35 grms of iodine, and then 2 c.c. of cone, nitric acid. A vigorous reaction sets in chlorine gas along with a little vapour of iodine escapes. When the reaction subsides, boil the liquid to drive off the dissolved chlorine, and then add another gram of iodine. Concentrate the soln. by evaporation, and collect the crystals of potassium iodate on a Buchner s funnel. The crude product is purified by dissolving it in about 150 c.c. of hot water, neutralize the soln. with potassium hydroxide, and on cooling crystals of the desired salt are obtained. 

B. 2,2 -Bipyridine. With the apparatus set as described above, 100 ml. of pure pyridine (Note 7) is poured into the dropping funnel, and the screw clamps are completely closed. Immediately afterward about 80 ml. of the pyridine is run slowly onto the catalyst from the dropping funnel. Under no circumstances is any air allowed to enter the flask. The flask is then shaken carefully in order to wet the catalyst as much as possible with pyridine. Another 80 ml. of pyridine is added in the same way, and the flask is shaken again. Finally 40 ml. of pyridine is added, and air is allowed to enter the flask. The connections to the Buchner flask are removed, and a reflux condenser is fitted. The reaction mixture is then boiled gently under reflux (Note 8). After about 48 hours the flask is allowed to cool to about 60°, and most of the liquid is decanted (Hoodt) and filtered through a sintered-glass funnel (Note 9) into a 500-ml. round-bottomed flask. Then 50 ml. of fresh pyridine is added to the catalyst in the reaction flask, and the mixture is heated to reflux... 

An alternative and quickly assembled apparatus employs a Buchner flask fitted with a ground glass joint to which is attached a dropping funnel. Ammonium chloride is placed in the flask, moistened with concentrated hydrochloric acid, and concentrated sulphuric acid added dropwise from the funnel at such a rate that the evolution of gas may be controlled. 

Add ethanol (100 mL) to the zinc in the Erlenmeyer flask and stir, and then decant the supernatant directly onto the sintered funnel, and apply a vacuum. Repeat this process three more times. Discard the filtrate from the Buchner flask. 

Medium sintered glass funnel and Buchner flask... 

Pour the mixture into a conical flask (250 mL) and cool the flask in an ice bath. S/ow/yadd water (20 mL) and carefully add potassium hydroxide pellets, while swirling the flask in the ice bath. Add sufficient pellets so that the pH of the viscous aqueous mixture is greater than 13 (test with pH papers). Add ethanol (150 mL) and filter the mixture under reduced pressure through a sintered filter funnel attached to a Buchner flask. Wash the residue with ethanol (3 x 10 mL), and evaporate the combined aqueous-alcoholic extracts on a rotary evaporator. 

Filter the product bis-toluenesulfonamide with gentle suction using a sintered glass filter funnel mounted on a Buchner flask (250 mL). Wash the product thoroughly with water (2 x 25 mL), saturated potassium carbonate solution (2 x 25 mL), water (2 x 20 mL) and methanol (2 x 25 mL). Dry the product in an electric oven (120°C) to yield a colourless solid, m.p. 234-5°C, (8.74 g, 91%). 

Pour the contents of the flask on to ice-water (c. 200 g) and filter off the resultant precipitate on a sintered glass filter funnel attached to a Buchner flask (500 mL). Wash the solid with water (3 x 20 mL). Take up the solid in dichloromethane (250 mL), dry the solution with anhydrous potassium carbonate, filter the mixture and remove the solvent under reduced pressure. 

Allow the stirred mixture to warm up slowly to room temperature and stir for an additional 3 h. Filter off the abundant white precipitate which forms on a sintered glass filter funnel attached to a Buchner flask. Wash the solid product on the filter funnel with cold methanol (3x5 mL), diethyl ether (2 x 25 mL) and dry the product under vacuum (0.1 mmHg) at room temperature. The product (13.4 g, 63%), m.p. 109 °C, is sufficiently pure to be used directly, but may be recrystallised from hot methanol if appropriate. 

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