Copy 1, Volume 4

Hand-book of chemistry / Translated by Henry Watts.

  • Gmelin, Leopold, 1788-1853
Date:
1848-1872
Catalogue details

Licence: Public Domain Mark

Credit: Hand-book of chemistry / Translated by Henry Watts. Source: Wellcome Collection.

    476/506 (page 432)
    ARG ae > ee st, aad ene a. NR Se Rae tie a = al Ng et ‘ ‘ 7 Sh aw + AAS PE re. - Brsmuruic Actp. Bi0®? es Wismuthsiure, Acide Bismuthique, Peroxide of Bismuth. When teroxide of bismuth is ignited with excess of potash- or soda-hydrate, and the air has access to the mixture—and likewise when chlorine acts upon the teroxide diffused through caustic potash,—a double salt is formed consisting of bismuthate of bismuth-oxide and the alkali. | According to Arppe, this latter process yields a hydrate of bismuthie acid, if the alkali is used in very large excess, and the anhy- drous acid if the quantity of alkali is somewhat less. | Preparation.—1. By treating brown bismuthate of bismuth-oxide and potash (p. 445) with a cold mixture of 1 part of nitric acid and 9 parts — water, then with a more dilute acid, and afterwards washing with water and drying. (A. Stromeyer, Pogg. 26, 549; Brandes, Schw. 69, 158.)— 2. By fusing bismuth-oxide with hydrate of soda, boiling the mass with excess of soda-ley, and washing the brown powder which separates, first with nitric acid, and then with water. (Fremy, Compt. rend. 15, 1108; also V. J. Pharm. 3, 30; see also Arppe, dnn. Pharm. 56, 239.) Calculation. Arppe. REN SR sive anmcs'n Savkabesives 78 RIM DE, 3. gk Bena a 84°26 BT eee Be Phe eget’ Dla hepy hace 15°74 | 1) (8am) SE Pe ero 3 253 LOGY: Fah vaca 100°00 Or: Calculation. Stromeyer. Brandes. Bi)? Biehl Boge A 95GB BES 95°14 3a 95 Nee Seas PGS G02 < tres aE 5 | US ane Beka anes BIO. Nya LOMO Trt ts ain, 100°00 c2. oe _Jacquelain regards bismuthic acid as BiO*: A. Stromeyer, from his analysis, assigns to bismuthic acid 13 times as much oxygen as to bismuth- oxide. The difficulty of obtaining bismuthic acid free from bismuth- oxide renders it probable that the oxygen in the former has been estimated too low rather than too high, and consequently that pure bismuthic acid is really BiO*, corresponding to antimonie acid. Decompositions.— At the temperature of boiling mercury, bismuthic acid is resolyed into oxygen gas and the yellow oxide, without giving off water. When a mixture of this acid with charcoal, sugar, or other organic substances is set on fire by a red-hot coal, it burns slowly away like tinder, without deflagration. Hydrogen gas reduces the acid to the state of oxide at a temperature below that at which the acid gives off, oxygen when heated alone; at a red heat, hydrogen reduces it to the metallic -state. Sulphurous acid, in the state of aqueous solution—but not in the - gaseous form,—slowly converts the acid into sulphate of bismuth-oxide. Oil of vitriol instantly disengages oxygen gas from it, dilute sulphuric acid more slowly. Phosphoric acid acts in the same manner. Cold nitric acid does not dissolve bismuthic acid, unless it contains nitrous acid ; heated nitric acid disengages oxygen and forms a solution of bismuth- oxide.—%i According to Arppe, bismuthic acid is distinguished from all - other oxygen-compounds of bismuth by being converted into the green oxide, BiOQ?,3Bi0*, when boiled with nitric.acid. —{—Cold hydrochloric acid gives off chlorine and forms a solution of. bismuth-oxide. Aqueous SS .