Glass apparatus

In most laboratories, drying ovens maintained at about 50° are available for the final drying of glass apparatus of all kinds. 

This brief account is intended to give only a general indication of the types of apparatus available. The firm which has pioneered the design and manufac ture of ground- glass apparatus is Quickfit and Quartz, Ltd., Quickfit Works,... 

The chlorosulphonic acid should he handled ucith great care, and always in a fumcTCUpboard. The technical acid is usually pure enough for the above preparation. If it is dark in colour, it can be further purified by care/yJ distilla- tion (preferably in an all-glass apparatus) and the fraction of b.p. 149-152" collected for use. 

Carbon tetrachloride. Although sand is of great value for extinguishing fires, it has the disadvantage that any glass apparatus around which the fire centres is usually smashed under the weight of the sand. Alternatively, therefore, for small fires carbon tetrachloride may be poured in a copious stream from a Winchester Bottle on to the... 

All glassware should be scrupulously clean and, for most purposes, dry before being employed in preparative work in the laboratory. It is well to develop the habit of cleaning all glass apparatus immediately after use the nature of the dirt will, in general, be known at the time, and, furthermore, the cleaning process becomes more difficult if the dirty apparatus is allowed to stand for any considerable period, particularly if volatile solvents have evaporated in the meantime. 

A shallow metal vessel containing sand, the so-called sand bath, heated by means of a flame, was formerly employed for heating flasks and other glass apparatus. Owing to the low heat conductivity of sand, the temperature control is poor the use of sand baths is therefore not... 

The elimination of the liquid baths and, in consequence, the absence of burns due to accidental breakage of the ordinary glass apparatus. 

All clamps holding glass apparatus should be lined with cork, attached by means of glue or seccotine , or with asbestos paper this will reduce the danger of fracture if excessive pressure is exerted on the clamp. 

A more satisfactory apparatus is depicted in Fig. II, 19, 3. With this all-glass apparatus, the whole side arm may be heated directly with a flame, thus enabling materials melting as high as 200° to be distilled with ease. A liquid forerun may be removed with a bulb pipette. A solid... 

Marketed by Baird and Tatlock (London) Ltd. t Marketed by the Scientidc Glass Apparatus Company. 

Sulphuryl chloride. The technical product should be fractionated, preferably in an all-glass apparatus the fraction b.p. 69-70° is collected. The pure substance has b.p. 69°/760 mm. 

Bromine. The commercial product may be dried (and partially purified) by shaking with an equal volume of concentrated sulphuric acid, and then separating the acid. Chlorine, If present, may be removed by fractionation in an all-glass apparatus from pure potassium bromide the b.p. is 59°/760 mm. The analytical reagent grade is satisfactory for most purposes where pure bromine is required. 

These dimensions were taken from U.S. A. sources cf. Scientific Glass Apparatus Catalogue, J—52 of 1952. 

P -f lOROH -f 5Br, — 2H3PO, -f lORBr -f 2H,0 The reaction is of general application with primary alcohols (n propyl to n hexadecyl) the yields are over 90 per cent, of the theoretical, but with secondary alcohols the yields are 50-80 per cent. in the latter case a small quantity of high boiling point by-product is also formed which can, however, be readily removed by fractional distillation. The reaction is conveniently carried out in a special all glass apparatus. 

I) It is preferable to use an all-glass apparatus for all the operations described in this preparation (see Section 11,60). 

An all-glass apparatus is recommended. Alternatively, a rubber stopper which has been used previously on several occasions (and therefore hardened somewhat) will be satisfactory. 

An all-glass apparatus is the most satisfactory (compare 8ectioos 11,54 et tq.). 

Diazomethane is easily decomposed by rough surfaces for this reason glass apparatus with scratches and also porous pot ( boiling stones ) should not be used. 

Since iodine monochloride attacks cork and rubber, the use of an all-glass apparatus is recommended. If it should come into contact with the skin, an elective antidote is dilute hydrochloric acid (1 1). 

Hydrazine hydrate of 95-100 per cent, concentration is a commercial product. The 40-60 per cent, solution may be concentrated to 80-85 per cent, strength by distillation with xylene in an all-glass apparatus. 

Water. Distilled water must be (a) redistilled in an all-Pyrex glass apparatus or (b) purified by passage through a column of cation exchange resin in the sodium form. For storage, polyethylene bottles are most satisfactory, particularly for very dilute (0.00 lAf) EDTA solutions. 

For many years fluorine has been deterrnined by the Willard-Winters method in which finely ground ore, after removal of organic matter, is distilled with 72% perchloric acid in glass apparatus. The distillate, a dilute solution of fluorosiUcic acid, is made alkaline to release fluoride ion, adjusted with monochloroacetic acid at pH 3.4, and titrated with thorium nitrate, using sodium a1i2arine sulfonate as indicator. 

Allyl acetate [591-87-7] M 100,1, b 103°, d 0.928, 04 1,40488, np 1.4004, Freed from peroxides by standing with crystalline ferrous ammonium sulfate, then washed with 5% NaHC03 followed by saturated CaCl2 soln. Dried with Na2S04 and fractionally distd in an all-glass apparatus. 

Butyl acrylate [I4I-32-2J M 128.2, b 59 /25mm, d 0.894, n 1.4254. Washed repeatedly with aqueous NaOH to remove inhibitors such as hydroquinone, then with distilled water. Dried with CaCl2. Fractionally distd under reduced pressure in an all-glass apparatus. The middle fraction was sealed under nitrogen and stored at 0° in the dark until used [Mallik and Das J Am Chem Soc 82 4269 I960]. 

It has been purified by distilling from K2CO3 under high vac and fractionated in an all-glass apparatus. The middle fraction is collected, degassed (seven or eight freeze-thaw cycles) and redistd under as high a vacuum as possible [Mohammad and Kosower J Am Chem Soc 93 2713 1971]. 

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