Works of the Cavendish Society: Gmelin, Leopold. Hand-book of chemistry. 18 v. & index. 1848-72, Volume 3

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1849 - Chemistry

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Page 4 - MnO, may, when combined with a larger quantity of oxygen, produce an acid, eg MnO3. In the base, the electro-positive nature of the metal exerts the greater power; in the acid, the electro-negative tendency of the oxygen has the advantage. These basic metallic oxides may be divided into three classes. Inorganic Alkalis. These oxides are soluble in water, — corrode animal substances, — have a soapy or urinous taste — change the colour of most blue or red flowers to green, the yellow colour of...
Page 75 - ... sulphuric acid. To separate the hydrochloric acid, the liquid is surrounded with ice, and mixed with sulphate of silver. In the first place, sulphate of silver, obtained by heating nitrate of silver in contact with oil of vitriol in a platinum crucible, is introduced in the form of powder into the liquid, — the whole being constantly stirred — till the liquid becomes clear, a sign that the hydrochloric acid is wholly or nearly precipitated. Any hydrochloric acid which may still remain must...
Page 135 - ... 3. When phosphorus is boiled with hydrate of potassium and alcohol, the non-inflammable gas is evolved, mixed with hydrogen gas and alcohol vapour, and there remains hypophosphite of potassium and a small quantity of phosphate, together with excess of potash (H. Rose). — 4. When phosphide of calcium is decomposed by concentrated hydrochloric acid (Dumas). — 6. Phosphorus, under the influence of light, decomposes water, producing phosphoric oxide [? red phosphorus] and phosphoretted hydrogen...
Page 75 - ... siphon : if it should evolve oxygen, — which it will do as soon as it is so far concentrated as to contain about 250 times its volume of oxygen — two or three drops of sulphuric acid must be added to it. The concentration must be stopped after a few days, when the liquid is brought to such a...
Page 76 - ... temperatures, peroxide of hydrogen is but very slowly decomposed ; at ordinary temperatures, it merely evolves a bubble of hydrogen now and then, the decomposition not being complete for months ; at 20° (68° F.) the escape of gas becomes more perceptible. By suddenly raising the temperature to 100°, this gradual escape of gas may be converted into a kind of explosion. Finally, there remains behind nothing but pure water. Sunshine does not appear to accelerate the decomposition at ordinary...
Page 420 - C. 5'96 pts. ammonia. 1 vol. water by absorbing 505 vols, ammonia, forms a solution occupying 1'5 vols., and having specific gravity 0'9 : this, when mixed with an equal bulk of water, yields a liquid of specific gravity 0'9455: whence it appears that aqueous ammonia expands on dilution.
Page 75 - The presence of a large quantity of sulphate of barium renders the filtration difficult. (If no phosphoric acid were present, the sesquioxides of iron and manganese would fall down by themselves, and give rise to a rapid evolution of oxygen gas ; but when they are mixed with phosphoric acid, they do not produce this effect.) Should the liquid still contain portions of these oxides, they must be separated by the addition of a slight excess of barytawater ; whereupon, the liquid must be immediately...
Page 74 - Preparation. — Pure baryta is prepared by igniting, in a porcelain retort, nitrate of barium free from iron and manganese. The baryta, broken into pieces about the size of a nut, is then put into a coated glass tube and heated to low redness, while a current of oxygen gas free from carbonic acid and dried by means of quicklime, is passed over it.
Page 75 - ... the filters squeezed between linen to get all out. The whole of the baryta must then be separated by carefully adding sulphuric acid in very slight excess, and filtering. The filtrate now contains nothing but water, peroxide of hydrogen, hydrochloric acid, and a very little sulphuric acid. To separate the hydrochloric acid, the liquid is surrounded with ice, and mixed with sulphate of silver. In the first place, sulphate of silver, obtained by heating nitrate of silver in contact with oil of...
Page 194 - Impure sulphide of manganese, obtained by igniting 6 parts of sulphate of manganese "with 1 part of charcoal (Berthier), or 5 parts of ignited oxide of manganese with 2 pnrts of sulphur and 1 part of charcoal : evolves the gas very rapidly; spoils by long keeping. Sulphide of iron and sodium, prepared by fusing 2 parts of iron pyrites with 1 part of anhydrous carbonate of soda. (Berthier.) — 6. By heating tersulphide of antimony with concentrated hydrochloric acid; the gas is not evolved in very...

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