Gas delivery tube

If it is desired to carry out the combined operations of stirring, refluxing, and addition of a liquid in a stream of gas, the apparatus of Fig. 77, 7, 12, a may be used the side tube for the gas is sealed on to the separatory funnel. For the passage of a gas into a stirred liquid, the aperture carrying the modified separatory funnel may be fitted with the device shown in Fig. 77, 7, 12, 6 the glass rod inside the tube is held in position by a short length of heavy-wall rubber tubing and is employed to clear the lower end of the gas delivery tube, should it become blocked with solid reaction product. 

Hydrobromic acid. Method 1 (from bromine and sulphur dioxide). A mixture of 600 g. (or 188-6 ml.) of bromine, 250 ml. of water and 760 g. of crushed ice is placed in a 1 6 litre round-bottomed flask and a rapid stream of sulphur dioxide (from a siphon of the liquefied gas) is passed into the flask, care being taken that the outlet of the gas-delivery tube is below the surface of the bromine layer. The rate of flow of the gas is adjusted so that it is completely absorbed. It is advisable to cool the flask in ice and also to shake the contents from time to time. The reduction is complete when the mixture assumes a uniform yellowish-brown or yellow colour, which is unaffected by further introduction of sulphur dioxide excess of the latter gas should be avoided as it will be... 

Gases may be added above or below the liquid surface by appropriate placement of a fritted-glass gas delivery tube in a rubber gasketed adapter (Fig. A3.5). 

Gas-abfuhrung, /. = Gasableitung. -abgabe, /. evolution or escape of gas. -ableitung, /. drawing off or removal of gas gas delivery tube, gas outlet, -ableitungsrohr, n. gas delivery tube, -abwehr, /. (MU.) gas defense. 

Gasentbindungs-flasche, /. gas-generating bottle or flask, gas generator, -rohr, n. gas delivery tube. 

Sixty grams of powdered sodium chloride are added to 180g of a 10% aqueous solution of ammonia and the mixture is allowed to stand, with occasional swirling, until almost all the salt has dissolved. The filtered solution is placed in a 1-liter flask fitted with a gas delivery tube leading almost to the bottom of the vessel and an exit tube of narrow-bore glass (3mm inner diameter). A steady stream of car-... 

Twelve grams of stannous chloride 2-hydrate are dissolved in 76ml of 3Af hydrochloric add contained in a 250ml suction flask fitted with a stopper and gas delivery tube leading well under the surface of the solution. The flask and contents are immersed in an ice hath and chlorine is passed in (2-8 bubbles/sec) until oxidation is complete. This is indicated by a persistent yellow color in the reaction mixture due to excess chlorine. The chlorination will take 15 to 30 minutes at the above rate of introducing the gas. The solution of hexachlorostannic (IV) acid is now warmed to 50°C and a solution of 6g of ammonium chloride in 25ml of 3Af Hydrochloric add at the same temperature are mixed together. The warm solution is evaporated to crystallization on the steam bath, cooled, filtered by suction, and drained well. The complex salt is dried in vacua over solid alkali. The mother liquor is worked up for further batches of crystals. 

The apparatus used takes several different forms, one of the simplest consisting of a two-necked Wolff s bottle, a thistle funnel being fitted into one neck and a gas delivery tube, connected with a calcium chloride tube, into the other. Beyond the calcium chloride tube is a hard glass tube, 40-45 cm. long and 5-6 mm. in diameter, drawn out at a certain position to a narrow, pointed tube. 

When all of the air and moisture have been displaced from the tube, the selenium is strongly heated with a Bunsen flame. A white deposit of selenium dioxide forms on the surface of the selenium but as soon as the temperature has become high enough, it sublimes away. At the same time, the remaining selenium melts to a viscous mass and eventually burns with a pale-blue flame. The sublimate collects on the gas-delivery tube and on the sides of... 

At the end of this time, when almost all the magnesium has reacted, the Dry Ice cold finger is replaced with a water condenser and the gas delivery tube with a dropping funnel. A solution of 142 g. (2.02 moles) of freshly distilled crotonaldehyde in 300 ml. of dry ether is added dropwise while the reaction mixture is stirred vigorously and cooled. The reaction mixture is allowed to stand at room temperature for 1 hour. 

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