A Manual of Chemical Analysis: Qualitative and QuantitativeLongmans, Green, 1904 - 476 trang |
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added alkali aluminium ammonia ammonium chloride ammonium sulphide analysis antimony apparatus aqueous arsenic barium chloride beaker boiled bromine bulb burette calcium carbon dioxide caustic chloric acid chromate cipitate colour compound containing converted cooled copper crucible cubic centimetres cuprous cyanide deci-normal decomposed dichromate dilute dissolved dried drop employed equivalent estimated evaporated excess expelled ferric ferrous filter filtrate flame flask funnel gives grams H₂O H₂S heated hydrochloric acid hydrogen hydroxide insoluble iodide iodine iron liquid litre magnesium manganese means measuring-tube mercury metals of Group mixture NH,HO nitric acid nitrogen normal oxalic acid oxide oxidised oxygen permanganate phosphate phosphoric acid pipette platinum potassium powder present reaction reagent reduced residue salts separated silicate silver chloride silver nitrate small quantity sodium carbonate soluble in water solution steam-oven strong substance sulphate sulphuretted hydrogen sulphuric acid temperature test-tube thiocyanate thiosulphate tube vapour volume washed weight white precipitate wire yellow zinc
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Trang ii - Works by GS NEWTH, FIC, FCS, Demonstrator in the Royal College of Science, London. CHEMICAL LECTURE EXPERIMENTS. With 230 Illustrations. Crown 8vo. , 6s. CHEMICAL ANALYSIS, QUANTITATIVE AND QUALITATIVE. With 100 Illustrations. Crown 8vo., 6s. 6d.
Trang 420 - ... which furnishes a supply of carbon dioxide with which to sweep out first the air and finally the products of the combustion from the tube. A roll of bright, copper gauze is introduced at the open end to prevent the escape of any nitrogen in the form of oxides of nitrogen. The tube is closed with a cork and delivery tube, and the nitrogen is collected in a measuring tube over caustic potash, whereby the carbon dioxide is removed. A piece of combustion tube is drawn off and sealed at one end before...
Trang 422 - ... and the heating of the combustion tube extended first to the roll of copper gauze, and then gradually along the tube toward the mixture of copper oxide and the fertilizer. The nitrogen that is evolved, together with the carbon dioxide now filling the air space of the tube, passes up into the burette, and the carbon dioxide being absorbed by the potash, the nitrogen alone collects. When the evolution of nitrogen is completed, the remainder of the sodium bicarbonate is heated, whereby a fresh supply...
Trang 376 - ... the mixture a measured volume of oxygen or air more than sufficient to combine with all the hydrogen. These are caused to unite (by methods to be described later), and the contraction ascertained by again measuring the gas. Since 2 volumes of hydrogen and 1 volume of oxygen unite to form water (which practically occupies no volume), two-thirds of the contraction represents the hydrogen originally present. When the gas to be estimated contains carbon and hydrogen (as in marsh gas, ethylene, etc....
Trang 376 - ... contact with an excess of a standard solution of barium hydrate. Barium carbonate is thereby precipitated, and the excess of barium hydrate is determined by titration with a standard solution of oxalic acid. 2. By Absorbing the Gas in a Suitable Reagent and Subsequent Measurement of the Residual Gas. — The carbon dioxide in a mixture of gases is determined by exposing a measured volume of the mixture to the action of caustic potash, and, after the whole of the carbon dioxide has been absorbed,...
Trang 423 - The fertilizer is mixed with dry granulated soda lime in a combustion tube closed at one end and containing a short layer of dry oxalic acid at its closed end, in order to furnish a stream of hydrogen wherewith to sweep out the ammonia at the end of the process. The evolved ammonia is absorbed in dilute acid contained in a Will and Varrentrap's bulb tube, which is attached to the combustion tube by means of a cork. The ammonia may be estimated either gravimetrically, by precipitation as ammonium...
Trang 331 - Fifty cubic centimetres of this solution are transferred by means of a pipette to a small flask, and diluted by the addition of about half the volume of air-free distilled water.
Trang 425 - In this way, the ammonia still filling the tube is driven out into the acid in the bulbs. The bulbs are then disconnected and the contents transferred to a beaker, the bulbs being thoroughly rinsed out with water. The excess of sulphuric acid present is titrated with normal sodium hydrate, according to the method described in Art. 9O, Quantitative Analysis, Part 1.
Trang 385 - FIo. o under different conditions should be reduced by calculation to one common standard. In exact methods of analysis, the latter plan is invariably adopted, but in the more rapid and somewhat rougher methods employed for technical purposes, the analysis may usually be carried out without disturbing the uniformity of conditions to an extent that will introduce any material error in the results. The recognized standard to which gaseous volumes are reduced is the volume that the gas would occupy...
Trang 390 - ... water with some of the gas in a stoppered bottle for a few minutes. Near each end of the sealed tubes, a slight scratch with a file is made. Over one end, a short piece of rubber tube is slipped, 'and the projecting portion of it filled up with water. The bent capillary, already entirely filled with water, is then introduced into this tube, and the latter secured with binding wire. In this way, all air is excluded from the joint. The lower end of the tube is dipped into a vessel of water. The...