Volumetric flask

“ Let us take a glass flask with a long neck of from two hundred and fifty to three hundred cubic centimetres capacity, and place in it some wort, with or without hops, and then in the flame of a lamp draw out the neck of the flask to a fine point, afterwards heating the liquid until the steam comes out of the end of the neck. It can then be allowed to cool without any other precautions; but for additional safety there can be introduced into the little point a small wad of asbestos at the moment that the flame is withdrawn from beneath the flask. ”

“ Wrap a duster or towel round the neck of the flask, and, holding it over a basin (in case of breakage) , pour gently a stream of cold water on to the flask. The steam inside is condensed, a partial vacuum is formed, and as long as any heat remains in the water, it will boil, whilst the stream of cold water is continued on the outside. ”

“ In the clasping talons of his left hand he held a long, slim flask that glinted even in that dim, confusing twilight. Two others, mates to the first, dangled at his waist. Lifting it high above his head, he swung his metal-clad right arm, and shattered the flask he held in his taloned left hand.
For an instant nothing happened, save that flittering bits of broken glass shimmered their way to the sand. Then the horde of noseless ones seemed to dissolve, as hundreds of limp and sprawling bodies sank to the sand. Perhaps a half of that great multitude seemed struck dead. ”

“ When night fell he emptied into the liquor a carefully computed amount of chloral hydrate, recorked it, shook it well, and placed it among sundry odds and ends in a corner of the office, where it would be overlooked by any thirsty caller, whose glance was certain to notice the bottle of whiskey in plain sight on a shelf. Against the consciousness of sixteen men that innocent-looking flask would tip the scales to its own side with an emphasis; and the marshal not only knew the proper dose for horses but also how to shove it down their throats with practiced ease and swiftness. ”

“ Some manufacturers who prepare their own pulp carry the concentration between 1.030 and 1.033. The method of obtaining this density is to use flasks graduated to hold 500 or 1000 grams of water at 200 degrees F., fill them with the hot pulp and weigh at once. For each flask there should be a proper counterpoise, and the balance be sensitive and weigh in grams. If the 1000-gram flask be used, the specific gravity will be the same as the weight of the pulp. With a valve funnel the flask may be filled level full and the weight taken in less than thirty seconds. ”

“ Gas chromatograph, FID, integrator, and column (see page 2530-1) . Vials, 2-mL, PTFE-lined caps. Syringe, 10-μL, readable to 0.1 μL. Volumetric flasks, 10- and 100-mL. Pipets, 1-mL, and other convenient sizes. ”

“ All that we observe is that the inner walls of the flask begin to trickle; the steam is condensed only on them, for there is no other fixed surface. If, now, some ordinary dusty air is blown into the flask, it at once appears to be filled with a thick, rolling cloud. The cloud is composed of as many drops as dust particles have been admitted. If only a little dust is admitted, all the vapor is precipitated upon it, and so loads it with water in a short time that it sinks in heavy drops to the ground. ”

“ The conditions necessary for success are— (1) that the apparatus should be in total darkness; [314] and (2) that there should be no substance present, such as alcohol or ammonia, [315] which, distilling over with the phosphorus-vapour, could destroy its luminosity. A convenient apparatus, and one certain to be in all laboratories, is an ordinary Florence flask, containing the liquid to be tested, fitted to a glass Liebig’s condenser, supported on an iron sand-bath (which may, or may not, have a thin layer of sand) , and heated by a Fletcher’s low temperature burner. ”

“ When the exhaustion « 106 » is complete (when a drop of petroleum-ether from the leather leaves no grease when allowed to evaporate on a clean glass) , the upper part of the apparatus is removed, and the ether is distilled off. If the flask has been previously weighed, it is maintained in an air-bath at 212°-248° F. (100°-120° C.) for some hours, allowed to cool, and weighed, when the gain of weight is the grease and oil. Paraffin would also be extracted and reckoned, and probably traces of resin if present. ”

“ Care must be taken that no particle of the sugar or solution is lost. To determine if all the sugar is dissolved, the flask is held above the level of the eye, in which position any undissolved crystals can be easily seen at the bottom. The character of the solution is now observed. If it be colorless or of a very light straw color, and not opalescent, so that it will give a clear transparent liquid on filtration through paper, the volume is made up directly with water to the 100 c.c. ”

“ When cold, froth can be immediately dissipated by adding a few drops of ether. In boiling liquids its formation may be prevented by adding paraffin wax; the wax melts and forms a ring on the surface of the liquid, which boils tranquilly in the centre.
3. Fractional Distillation.—By fractional distillation is meant the separation of a mixture having components which boil at neighbouring temperatures. The distilling flask has an elongated neck so that the less volatile vapours are condensed and return to the flask, while the more volatile component passes over. ”

“ Flamborough noticed a conical flask containing some limpid liquid, and a stoppered bottle. Markfield clamped a dropping funnel, also containing a clear liquid, so that its spout entered the conical flask; and by turning the tap of the funnel slightly, he allowed a little of the contents to flow down into the flask.
“I hope the smell doesn't trouble you,” he said, in a tone of sour apology. “It's the triethylamine I'm mixing with the tetranitromethane in the flask. Rather a fishy stink it has.” ”

“ Feverishly the man in the glass mask uncorked a small flask containing an opaque fluid resembling liquid gold. His hand shook, but by an effort of will he steadied it. Then—one, two, three drops he added to the contents of the test-tube, which, now, had become perfectly black. He replaced the stopper in the little flask. ”

“ All that is necessary is to immerse the exhausted flask in boiling oxygen, and then to allow the second gas to enter from a gasometer by opening the stop-cock until the pressure is equalized. The stop-cock being closed, the flask is now taken out of the liquid oxygen and left in the balance-room until its temperature is equalized. It is then weighed against a similar flask used as a counterpoise. Following such a method, it has been found that the weight of 1 litre of oxygen vapour at its boiling point of 90.5° absolute is 4.420 grammes, and therefore the specific volume is 226.25 cc. ”

“ By rotating the disk the tubes may be successively brought under the end of the condenser. Boiling under reduced pressure has one very serious drawback, viz. the liquid boils irregularly or “bumps.” W. Dittmar showed that this may be avoided by leading a fine, steady stream of dry gas-air, carbon dioxide, hydrogen, &c., according to the substance operated upon—through the liquid by means of a fine capillary tube, the lower end of which reaches to nearly the bottom of the flask. ”

“ There is scarcely any possibility of foreign substances of any kind passing through the stuffing box, so that water, unless chemically tainted or poisoned by mineral solutions, can be rendered fit for use in two or three minutes by the use of either the metal flask or stopper. ”

“ THE DETERMINATION One gram of the substance to be analyzed is brought into a digestion flask with approximately 0.7 grams of mercuric-oxide, and 20 cubic centimeters of sulphuric acid, and the flask is placed on the frame described in an inclined position, and heated below the boiling point of the acid for from five to fifteen minutes, or until frothing has ceased. The heat is then raised until it boils briskly. No further attention is required until the contents of the flask have become a clear liquor, which is colorless, or, at least, has only a very pale straw color. ”

“ What’s the good of having a flask out there? We can’t start climbing over rocks and wading through rivers to find it.’
‘But this car’s here, just round the corner,’ he said. ‘You’re forgetting that. I can easily slip out and get the flask.’
‘Of course!’ she cried. ‘I was thinking of [133] our car. Just a minute then, and I’ll come to the door with you. I’ll put my boots on first.’
‘Have you got a torch?’ he asked. When he discovered that she had, having carried Sir William’s through the darkness, he continued: ‘Well, if you let me have that, I can get the flask in a minute. ”

“ A large flask, provided with a bent glass tube for conveying the gas, and a tube-funnel for introducing the acid, is the most convenient form of apparatus. A tubulated retort may be used, but the generating flask or bottle is to be preferred.
Carbonic acid is rapidly evolved, and may be collected, with some loss, over water in the pneumatic trough. If required dry, the gas must be passed over fragments of fused chloride of calcium, placed in a large tube, or through a small quantity of concentrated sulphuric acid, and collected by displacement or over mercury. ”

“ Add distilled water of laboratory temperature until the lowest point of the meniscus is level with the graduation on the neck of the flask and remove any drops of water that may be on the neck above the graduation by means of a strip of filter paper; make the solution thoroughly uniform by pouring it out into a dry beaker and back into the flask several times. Measure off 50 cc. of the solution in a measuring flask, or pipette, either of which before use should, unless they are dry on the inside, be rinsed out with at least two small portions of the soda ash solution to displace any water. ”

“ If the vapours be sparingly soluble in the liquids there will exist a mixture having a greater vapour pressure than that of any other mixture. The vapour pressure-composition curve will now be concave to the axis of composition, the minima corresponding to the pure components. On distilling such a mixture, a mixture of constant composition will distil first, leaving in the distilling flask one or other of the components according to the composition of the mixture. An example is propyl alcohol and water. ”

“ The liquor is carefully decanted into a clean beaker and is then thrown into a jar marked "waste silver." About 40 c.c. of the second parting acid, heated to boiling, is then poured into the flask, which is then replaced on the hot plate. The boiling is continued for 15 or 20 minutes or even longer. At this stage bumping has to be specially guarded against; after a little experience it is easy to see when this is imminent and the flask should be withdrawn to a cooler part of the plate; it is better to prolong the heating at a temperature below boiling than to run the risk of disaster. ”

“ The pointed end of the flask passed into a strong glass tube .39 to 46 inch in its inner diameter, within which he had placed a piece of tube of small diameter, open at both ends, free to slip into the larger tube, and inclosing a portion of one of the small plugs of cotton loaded with dust. The larger glass tube is bound to a brass tube in form of a T, furnished with stopcocks, one of which communicates with the air-pump, another with the heated platinum tube, and the third with the flask, by means of the large tube which contains the smaller one with the cotton. ”

“ When the ether layer is distinct, the acid liquor is run off, and the ether solution transferred to A. The whole of the ether solution is washed in the apparatus two or three times with a little water, the flask A removed to the water bath, the ether driven off, the last traces of ether and water being removed by placing the flask in a drying oven heated from 107 to 110° C., where it must remain at least twenty minutes. ”

“ His plan, as communicated to the American Chemist, is to have, in some suitable place in the ship, a flask or flasks about three feet in length, and one foot in diameter, containing about 100 pounds of the gas in the liquid state. From the top of the flask, a small iron pipe is to be permanently fitted along the waterways throughout the entire length of the ship. From this main pipe branch pipes pass to every storeroom and compartment, each branch to be controlled separately by means of a cock. ”

“ The condensing apparatus must also be conditioned by the volatility. With difficulty volatile substances, e.g. nitrobenzene, air cooling of the retort neck or of a straight tube connected with the distilling flask will suffice; or wet blotting-paper placed on the tube and the receiver immersed in water may be used. For less volatile liquids the Liebig condenser is most frequently used. ”

“ A warm waistcoat—sufficiently low at the back to give protection to the kidneys—is, I understand, essential. We must also procure a flask.”
“Well, I shouldn’t if I were you. If you take whiskey when you’re on duty, and then anything happens, you only put yourself in the wrong.”
“I had forgotten my cocoa flask” (page 139) .
138“My dear Eliza,” I said, “I was not dreaming of taking stimulants while on duty. Afterwards, perhaps, in moderation, but not during. I was referring to one of those flasks which keep soup or cocoa hot for a considerable period. ”

“ The flask is then well cooled with an ice-and-salt mixture, until the temperature of the acetone is between 0'0 and 5'0. Stirring is started, and 4160 cc. of commercial concentrated sulfuric acid is run in at such a rate that the temperature of the mixture never rises above about 10'0. This addition is accomplished in about five to ten hours. The stirring is continued for three to four hours longer, while the flask still remains immersed in the original freezing mixture to which no further amount of ice is added. ”