Receiving flask

Fractional Distillation under Reduced Pressure. One great disadvantage of the simple vacuum-distillation apparatus shown in Fig. 12(a) is that, if more than one fraction distils, the whole process has to be stopped after collecting each consecutive fraction, in order to change the receiver F. This may be overcome by replacing the simple receiving flask F by a pig (Fig. 13) which collects consecutive... 

Ethyl bromide soon distils over, and collects as heavy oily drops under the water in the receiving flask, evaporation of the very volatile distillate being thus prevented. If the mixture in the flask A froths badly, moderate the heating of the sand-bath. When no more oily drops of ethyl bromide come over, pour the contents of the receiving flask into a separating-funnel, and carefully run oflF the heavy lower layer of ethyl bromide. Discard the upper aqueous layer, and return the ethyl bromide to the funnel. Add an equal volume of 10% sodium carbonate solution, cork the funnel securely and shake cautiously. Owing to the presence of hydrobromic and sulphurous acids in the crude ethyl bromide, a brisk evolution of carbon dioxide occurs therefore release the... 

Nitrobenzene (and many other liquid organic compoimds containing nitrogen) is appreciably toxic and its vapour should not be allowed to escape into the atmosphere of the laboratory the delivery tube of the condenser should pass well into the mouth of the receiver flask. The liquid is also a skin poison if it Is accidentally spilled on the skin, it should be removed by washing with a litt e methylated spirit, followed by soap and warm water. 

Remove the condenser, then with the aid of a funnel add the water slowly, keep stirring. If the solution is too hot the water will evaporate and make a big mess. As the water is added you will notice that loads of stodgy crapp will form, this is normal, connect the condenser for the distillation with a receiving flask at least 500ml in capacity. 

The receiving flask contents should contain a very pure product. There is no need to clean up any further. For the next stage however they wilt need to be dried over sodium sulphate. This can either be done now or later. Now is better, dry your product before you weigh it and place it in a screw capped bottle ready for the Grignard reaction. 

THF into the sep funnel. It is recommended that an iodine crystal is placed in the reaction flask and before the condenser is attached, nitrogen should be blown Into the receiving flask to remove any air. As / didn t have any nitrogen available I skipped this step but I did place one small crystal of iodine into the reaction flask. When the iodine is added the solvent will begin to turn brown. Although this looks like the iodine is just dissolving it would appear from what I have read that this is also caused by the reaction. 

Setup your glassware for simple distillation with a claisen adapter, three way adapter, pressure-equalized addition funnel, water cooled condenser, vacuum adapter and receiver flask to catch any condensed solvent vapors. 

The bath temperature should be maintained below 70-75°. Bistillation was carried out using a Claisen head, and the receiving flasks were immersed in ice. 

Bromine (7 ml) is added dropwise to a mixture of white sand (14 g) and red phosphorus (3 g, dried at 165° under vacuum) moistened with 5 ml of deuterium oxide. The apparatus is fitted with an exit tube to allow the liberated deuteriobromic acid to pass through two U-tubes and into a receiving flask. The first trap contains glass beads and is cooled in an ice-salt slurry. The second contains glass beads and red phosphorus moistened with deuterium oxide. The deuterium bromide gas is collected in the appropriate solvent at ice bath temperature. A small amount of phosphorus pentoxide should be added to remove any deuterium oxide if anhydrous reagent is required. 

When the removal of the ether is complete, the condenser is drained of water and the receiving flask is immersed in an ice bath. The condenser is heated by steam, if necessary, to prevent solidification of the distillate in the condenser. The distillation is resumed affording e i/o-tetrahydrodicyclopentadiene, bp 191-193, about 50 g (98%). The melting point varies with the purity of the starting diene but is usually above 65. ... 

The mixture is filtered into a 500-ml round-bottom flask, and methanol and water are removed by distillation under vacuum (bath temperature 50-60°) until the residual amine oxide hydrate solidifies. The flask is fitted with a magnetic stirrer and a short Vigreux column, and the receiving flask is cooled in a Dry Ice-acetone bath. The flask... 

The apparatus consists of a 100-ml distilling flask equipped with a dropping funnel and arranged for distillation through an efficient condenser. The condenser is connected to two receiving flasks in series, the second of which contains 20-30 ml of ether. The inlet tube of the second receiver dips below the surface of the ether and both receivers are cooled in ice baths. All connections in the setup are made with bored cork stoppers and all glass tubing is fire polished (Fig. 17.1). 

Auffang-gefass, n. collecting vessel, receiver, -kolben, m. receiving flask, -rohr, n., -rfihre, /. collecting tube, pipe or cylinder, -schale, /. collecting dish or basin drip pan. auffkrben, v.t. dye anew, redye. 

The temperature of the reaction flask is raised to 100-110°, and the receiving flask is cooled in a dry ice-isopropyl alcohol... 

If an emulsion has formed, it may be broken by acidifying with hydrochloric acid, whereupon two clear layers are obtained. The benzene solution may be dried and then fractionated or preferably, it may be steam distilled. In the latter case it is transferred to a r-1. Claisen flask, the flask is set in an oil bath (Note 3) and the benzene distilled. Steam is then passed in, and after the last of the benzene is removed, the p-bromodi-phenyl distils with the steam. The temperature of the oil bath is held at 170° in order to hasten the distillation. The product solidifies in the condenser and receiving flask. There is obtained 23-24 g. of -bromodiphenyl which melts at 85-86.5°. 

Adipic acid, 146.1 g (1.0 mol), and 186.2 g (3 mol) of 1,2-ethanediol are weighed into a 500-mL glass reactor equipped with a mechanical stirrer, a nitrogen inlet, and a distillation head connected to a condenser and a receiver flask. The reactor is placed in a salt bath preheated at 180°C and the temperature is then raised gradually to 220°C (see note at end of procedure) until the greater part of water has been removed (3 h). The reactor is cooled down to 160°C and vacuum is applied slowly to about 0.07 mbar (30 min). Excess free 1,2-ethanediol begins to distill and temperature is raised gradually to 190°C (90 min). The reaction is continued for an additional 1 h. Pressure is then ramped to atmospheric widi a... 

The submitters recommend that the solvent be distilled under nitrogen into a two-necked receiving flask fitted with a three-way stopcock. The receiving flask is separated from the distillation apparatus under a rapid nitrogen flow and fitted quickly with a rubber septum. The solvent is then transferred to the reaction vessel by needlestock techniques. 

A stainless steel cannula with a 2-mm. inside diameter and both ends sharpened is inserted through the septum into the receiving flask above the surface of the liquid, and a stream of nitrogen is passed briefly through the stopcock and out the cannula to remove air. The other end of the cannula is then inserted through the septum on the reaction vessel, the end of the cannula in the receiver is pushed below the surface of the liquid, and the solvent is forced into the reaction vessel with nitrogen pressure. 

Diazomethane Follow essentially Aldrich Chemical Company s procedure for the Preparation of ethereal-alcoholic solution of diazomethane A 25-mL volume of ethanol is added to a solution of 5 g of potassium hydroxide in 8 mL of water in a 100-mL distillation flask fitted with a dropping funnel and a distillation condenser. The lower end of the condenser extends through and just below the neck of a 250-mL Erlenmeyer receiving flask, the latter being cooled in an ice-bath. The distillation flask containing the alkaline solution is heated in a water-bath to 65 °C and the contents of the flask are agitated with a magnetic stirrer. A solution of... 

Color photo of a keugelrohr distillation receiving flask full of DMT crystals. 

Dining removal of free iodine from hydriodic acid by distillation from red phosphorus, phosphine was produced. When air was admixed by changing the receiver flask, an explosion occurred. Omission of distillation by boiling the reactants in inert atmosphere, and separating the phosphorus by fitration through a sintered... 

In the meantime, a mixture of 79 g. (0.55 mole) of cuprous bromide (Note 3) and 80 ml. (0.6 mole) of 48% hydrobromic acid (Note 1) is heated to boiling in a 5-1. round-bottomed thrcc-necked flask, equipped with a condenser set for distillation and provided with a 2-1. receiving flask, a steam inlet tube closed by a screw clamp, and a separatory funnel. About one-fourth of the diazonium solution is transferred to the separatory funnel, without filtration, and immediately run into the cuprous bro-mide-hydrobromic acid solution, which is kept boiling over a free flame, at such a rate that boiling is continuous. When the separatory funnel is nearly empty a further portion of the cold... 

---