Funnel glass joint

II, 36, 1 is almost self explanatory two ground glass joints are used, but these may be replaced by rubber stoppers, if desired. The crude substance is placed in the flask A. Stopcocks 1 and 2 are closed, and the apparatus is exhausted through tap 3 the indifferent gas is then allowed to enter the apparatus to atmospheric pressure. The evacuation and filling with inert gas are repeated several times. The solvent is added through the tap funnel B. 

Mechanical stirring is not strictly necessary however, severe bmnping is sometimes encountered if it is not used. Hydrazine attacks both cork and rubber. If a dropping fimnel with ground glass joint is not available, an ordinary dropping funnel may be placed at the top of the reflux condenser. 

A hydrolysis unit is constructed using the commercially available glassware shown in Figure 2. The collection funnel should be calibrated and marked for volumes of 35 and 85 mL. All 20/40-glass joints of the hydrolysis unit should be assembled with Teflon sleeves and secured with spring clamps to prevent loss of the volatile EMA and HEMA analytes. 

Cylinders, graduated mixing with ground-glass joints and stoppers, 50-, 250-mL Flasks, round-bottom with 24/40 ground-glass joint, 500-mL Flasks, volumeAic, Class A, various sizes Funnels, glass... 

A. Preparation of a-bromoisobutyryl bromide. To a mixture of 250 g. (2.85 moles) of isobutyric acid and 35 g. (1.13 moles) of red phosphorus in a 1-1. three-necked flask, fitted by ground-glass joints to a dropping funnel, mechanical stirrer, and reflux condenser, is added, dropwise with stirring, 880 g. (5.5 moles) of bromine. After the addition is complete, the solution is warmed to 100° over a period of 6 hours. The unreacted bromine and hydrogen bromide are removed under reduced pressure (30 mm.). The a-bromoisobutyryl bromide is decanted from the phosphorous acid and fractionated through a short helices-packed column. After a considerable fore-cut, the main fraction, 493-540 g. (75-83%), is collected at 91-98° (100 mm.). 

The stem on a sep funnel can either be straight or have a ground glass joint on the end (Fig. 53). The ground glass joint fits the other jointware you may have and can be used that way as an addition funnel to add liquids or solutions... 

Look at Fig. 83a. It is a true sep funnel. You put liquids in here and shake and extract them. But could you use this funnel to add material to a setup NO. No ground glass joint on the end and only glass joints fit glass joints. Right Of course, right. 

So a compromise was reached (Fig. 856). Since you ll probably do more extractions than additions, with or without reflux, the pressure-equalizing tube went out, but the ground glass joint stayed on. Extractions no problem. The nature of the stem is unimportant. But during additions, you ll have to take the responsibility to see that nasty vacuum buildup doesn t occur. You can remove the stopper every so often or put a drying tube and inlet adapter in place of the stopper. The latter keeps moisture out and prevents vacuum buildup inside the funnel. 

Apparatus 250-ml two-necked (vertical necks ), round-bottomed flask, equipped with a evacuable dropping funnel and a very short (-5 cm) Vigrcux column, connected to a short condenser and a single receiver cooled in a bath at -50 C or lower. B24 or B29 glass joints should be used. 

In a 2-1. three-necked, round-bottomed flask with glass joints are placed 850 g. of commercial glacial acetic acid and 100 ml. of water. The flask is fitted with a stirrer. One of the side necks carries a reflux condenser and a thermometer reaching to the bottom of the flask the other is provided with a stopper which can be replaced by a powder funnel. The flask is surrounded by a water bath. At room temperature 156 g. (1.53 moles) of 98-99% chromium trioxide (Note 1) is added, and the mixture is stirred for about 15 minutes to effect solution of the oxidizing agent. 

The mixture is cooled to 15°, and the precipitated potassium bicarbonate is collected on a Buchner funnel. The solid (weight 70-72 g.) is washed on the funnel with 100 ml. of 95% ethanol. The combined filtrate and wash liquor is transferred to a 5-1. round-bottomed flask and made slightly acid Caution Note 1) with dilute hydrochloric acid (about 15-20 ml. of the 10% acid is required). The solution is then concentrated under reduced pressure to a semi-solid residue (Note 1). The cooled residue is shaken with a mixture of 300 ml. of water and 500 ml. of ether. The material dissolves completely the water layer is separated and washed with 200 ml. of ether. The ether solutions are combined, dried over 20 g. of calcium chloride, filtered into a 2-1. round-bottomed flask equipped with a glass joint, and concentrated by distillation (heating on a steam bath). The crude ethyl /3-phenyl-/3-cyanopropionate remains as a clear red oil weighing 130-140 g. It is sufficiently pure for use in the next step (Note 2). 

Assemble an apparatus as shown in Fig. 102. Lubricate the ground-glass joints with phosphoric acid. Fill the apparatus with dry carbon dioxide using offtake 2. Pour 10 ml of dry carbon disulphide from dropping funnel 3 into flask 1. 

Lubricate the ground-glass joints in the apparatus with a concentrated sulphuric acid solution. Clean a piece of metallic aluminium with emery paper, make 10-12 g of shavings from it, and put it into flask 1. Pour 30 ml of dry bromine into dropping funnel 2. This amount of bromine is not sufficient for the aluminium to enter into the reaction completely (why is excess aluminium taken )... 

Preparation of Zinc Iodide in Absolute Ether. Assemble an apparatus (see Fig. 119a), replacing dropping funnel 4 with a glass stopper provided with a ground-glass joint. Put 3 g of powdered zinc,... 

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