Distillation thermometer

Initial Boiling Point The temperature indicated by the distillation thermometer at the instant the first drop of condensate leaves the end of the condenser tube. 

Sheet 1 thermometer with standard ground joint, distillation thermometer (to be calibrated)... 

Data of the distillation thermometer with standard ground joint according to TGL 40-339, DIN 12784/55... 

Assemble the distillation apparatus described in Specification E 133 using flask D (250-mL bulb volume), flask support board with 51-mm diameter opening, and graduated cylinder C (200-mL capacity). A thermometer is not required but the use of the ASTM Hi Distillation Thermometer 8F or 8C as prescribed in Specification E 1 or the IP High Distillation Thermometer 6C, as prescribed in... 

Thermometer—Va ASTM Solvents Distillation Thermometer used in the test shall be as prescribed in the specifications for the material being tested. If no thermometer is specified in the material specification, select one from Table 1 with the smallest graduations that will cover the entire distillation range of the material being tested. Table 1 lists several ASTM solvents distillation thermometers which are suitable for testing industrial aromatic hydrocarbons, and which meet the requirements of Specification E 1. 

Support the distillation thermometer in the neck of the flask by means of a cork stopper with the thermometer vertical and centered in the neck of the flask and in such a position that the top of the bulb (or top of contraction bulb if present) is level with the lowest point of juncture between the side tube and the neck of the flask (see Fig. 3). 

Adjust the heat input so that the distillation proceeds at a rate of 4 to 5 mL/min (approximately 2 drops per second), and move the receiving cylinder so that the tip of the condenser tube touches one side of the cylinder after the first drop falls (initial boiling point). Record the readings of the distillation thermometer a r collecting 5,10,20, 30,40, 50, 60, 70, 80, 90, and 95 mL of distillate. 

Without changing the heater setting, continue distillation beyond the 95 % point until the dry point is observed. Record the temperature at this point as the dry point (Section 3). If a dry point is not obtained (that is, if active decomposition should occur before the dry point is reached, as evidenced by a rapid evolution of vapor or heavy fumes or if there is liquid remaining on the bottom of the flask when the maximum temperature is observed on the distillation thermometer), record this fact. 

When a dry point cannot be obtained, report as the end point the maximum temperature observed on the distillation thermometer or final boiling point (Section 3). When active decomposition is encountered, the rapid evolution of vapor and heavy fumes is usually followed by a gradual decrease in the cfistillation temperature. Record the temperature and report as the decomposition point (Section 3). If the expected drop in temperature does not occur, record the maximum temperature observed on the distillation thermometer 5 min after the 95 % point has been reached, and report as end point, 5 min. This notation shows that a true end point could not be reached within the given time limit. In any event, the end point should not exceed 5 min after the 95 % point... 

The thermometer should be so arranged that the top of the bulb is just level with the centre of the side-arm of the distilling-flask. 

Round-bottomed flasks (Fig. 22(A)) of various sizes and having necksof various lengths and widths. They can be closed with stoppers (Fig. 22(B)), or fitted with any of the following units reflux air-condensers (Fig. 22(C)) or water condensers (Fig. 22(D)) distillation heads, of the simple knee-tube type (Fig. 22(E)), or with a vertical joint (Fig. 22(F)) for thermometers, etc., or with... 

The distillation heads Fig. 22(F) and Fig. 22(G) can be fitted with thermometers having a ground-glass cone just above the bulb (Fig. 22(M)). These are expensive, and it is usually more convenient to fit a thermometer pocket (Fig. 22(N)) which consists of a small well , fitting as shown into the neck of the flask. A small volume of mercury is placed in the well just to cover the bulb of a conventional thermometer, and thus provides excellent thermal contact between the thermometer and the sides of the pocket. 

Fig. 23(E) shows a distillation assembly particularly useful for distilling ether from an ethereal extract. When all the ether has distilled over, the drop-ping-funnel may be replaced by a thermometer for distillation of the residual liquid the adaptor A and the receiver B can then be replaced by the simple adaptor shown in Fig. 23(D) and a flask or bottle of suitable size.

Now filter the ether through a fluted filter-paper directly into a 100 ml. distilling-flask, and then equip the latter with a 100° thermometer and a double-surface condenser to the end of the latter attach a receiver with a rubber delivery-tube precisely as before. Place the flask cautiously in a water-bath, the contents of which have previously been heated to about 60° at some distance from the apparatus arrange the depth of the flask in the water-bath so that the ether distils slowly over. Collect the fraction boiling between 34-39°. Yield, 25 g. (35 ml.). Not more than a verv small residue of etlianol should remain in the flask. 

After about 20 minutes, when the liquid should be dry, filter it through a small fluted filter-paper into a 100 ml. distilling-flask attached to a water-condenser. Add some fragments of unglazed porcelain to the ethyl acetate, fit a 100° thermometer to the flask, and place the latter on a cold water-bath, which is then brought to the boil. Some ether is always formed as a by-product with the ethyl acetate, and by these means is carefully distilled off as a... 

The hydrolysis of as little as 0 5 ml. of the ester can be carried out in the combined reflux-distillation apparatus shown in Fig. 38 (p, 63). Pass a stream of cold water through the vertical condenser. Place in the 10 ml. pear-shaped flask 0 5 ml. of the ester, 5 ml. of 10% NaOH solution and one or two minute fragments of unglazed porcelain and heat the mixture gently for 15 minutes so that the vapours do not rise more than about half-way up the vertical water ondenser. Now run the water out of the ver ical condenser, insert a thermometer at the top, and pass water through the inclined condenser. Heat the flask sufficiently strongly to collect 1--2 ml. of distillate. This is dilute ethanol. 

Fit the flask with a 100° thermometer and a water-condenser, and distil the ethyl iodide carefully from a water-bath, collecting the fraction which distils between 68° and 73°. Yield, about 24 g. 

The crude acetonitrile contains as impurity chiefly acetic acid, arising from the action of phosphoric acid on the acetamide. Therefore add to the nitrile about half its volume of water, and then add powdered dry potassium carbonate until the well-shaken mixture is saturated. The potassium carbonate neutralises any acetic acid present, and at the same time salts out the otherwise water-soluble nitrile as a separate upper layer. Allow to stand for 20 minutes with further occasional shaking. Now decant the mixed liquids into a separating-funnel, run off the lower carbonate layer as completely as possible, and then pour off the acetonitrile into a 25 ml, distilling-flask into which about 3-4 g. of phosphorus pentoxide have been placed immediately before. Fit a thermometer and water-condenser to the flask and distil the acetonitrile slowly, collecting the fraction of b.p. 79-82°. Yield 9 5 g. (12 ml.). 

Place in the flask 2 g. of benzophenone, 15 ml. of isopropanol and 2 5 g. of aluminium isopropoxide. This mixture has now to be heated gently under reflux so that the temperature registered by the thermometer in the column does not exceed 80°, i.e., so that only acetone distils. For this purpose, the flask should preferably be heated in an oil-bath direct heating, even over an asbestos sheet, may cause local overheating and decomposition the use of a water-bath on the other hand may make the column undesirably damp. 

Then, while the diazonium solution is standing in ice-water, dissolve 55 g. of powdered copper sulphate (CuS04,5Ha0) in 200 ml. of water contained in a 1500 ml. flat-bottomed flask, for which a steam-distillation fitting is available for subsequent use. Place a thermometer in the copper sulphate solution and warm the latter to 60-65 . Now cautiously add a solution of 60 g. of powdered potassium cyanide in too ml. of water to the copper... 

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