ISBN: 1236324102

[EAN: 9781236324108], Neubuch, [PU: RareBooksClub], FREDERICK PEARSON TREADWELL,HISTORY,ANALYTIC, This item is printed on demand. Paperback. 224 pages. Dimensions: 9.7in. x 7.4in. x 0.5in… Plus…

[EAN: 9781236324108], Neubuch, [PU: RareBooksClub], FREDERICK PEARSON TREADWELL,HISTORY,ANALYTIC, This item is printed on demand. Paperback. 224 pages. Dimensions: 9.7in. x 7.4in. x 0.5in.This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1921 Excerpt: . . . 6 OH-6 H20 3 021 2Au. The precipitated metal appears brownish-black by reflected light, but bluish-green by transmitted light; 0. 03 mg. gold in 10 cc. of liquid suffices to give a reddish coloration with a bluish shimmer. 9. Zinc. --The following gold test is very sensitive: t To a few drops of a dilute gold solution add a few drops of arsenic acid, two or three drops of ferric chloride solution, and two to three drops of hydrochloric acid. Dilute the mixture to 100 cc. , and drop in a piece of zinc. Around the zinc the solution assumes a purple color, which, by moving the zinc in the solution, is disseminated through it, making it appear pink or purple. If the solution contains 0. 03 mg. of gold, within fifteen minutes a beautiful reddish color will be noticed. Besides the above reagents many others, such as formaldehyde in the presence of alkali, hydrazine sulfate, etc. , are capable of reducing gold from its solutions. 10. Hydrogen Sulfide precipitates, in the cold, black gold disulfide from gold solutions: 2 Au 3 H2S-6 H S Au2S2. Gold disulfide is insoluble in acids; but is readily soluble in aqua regia, forming auric chloride, AuCl3. The disulfide is difficultly soluble in ammonium sulfide, but more readily soluble in potassium polysulfide, forming a sulfo salt: Au2S, K2S, 2 KAuSs. From this solution hydrochloric acid precipitates a yellowish-brown sulfide: 2 KAuS. 2 2 H-2 K H2S Au2S, (). From a hot solution, hydrogen sulfide precipitates brown, metallic gold: 8 Au 3 H2S 12 H20--30 H 3 SOr 8 Au. The finely divided metallic gold is soluble in hot potassium or sodium polysulfide, forming a thio salt: 2 Au K2S4-2 KAUS2. On account of its softness, gold is always alloyed with silver and copper when used for c. . . This item ships from La Vergne,TN.<

2012, ISBN: 1236324102

[EAN: 9781236324108], Neubuch, [PU: Rarebooksclub.com, United States], Language: English . Brand New Book ***** Print on Demand *****.This historic book may have numerous typos and missin… Plus…

[EAN: 9781236324108], Neubuch, [PU: Rarebooksclub.com, United States], Language: English . Brand New Book ***** Print on Demand *****.This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1921 Excerpt: .+ 6 OH -6 H20 + 3 021 +2Au. The precipitated metal appears brownish-black by reflected light, but bluish-green by transmitted light; 0.03 mg. gold in 10 cc. of liquid suffices to give a reddish coloration with a bluish shimmer. 9. Zinc.--The following gold test is very sensitive: t To a few drops of a dilute gold solution add a few drops of arsenic acid, two or three drops of ferric chloride solution, and two to three drops of hydrochloric acid. Dilute the mixture to 100 cc., and drop in a piece of zinc. Around the zinc the solution assumes a purple color, which, by moving the zinc in the solution, is disseminated through it, making it appear pink or purple. If the solution contains 0.03 mg. of gold, within fifteen minutes a beautiful reddish color will be noticed. Besides the above reagents many others, such as formaldehyde in the presence of alkali, hydrazine sulfate, etc., are capable of reducing gold from its solutions. 10. Hydrogen Sulfide precipitates, in the cold, black gold disulfide from gold solutions: 2 Au+++ + 3 H2S-6 H+ + S + Au2S2. Gold disulfide is insoluble in acids; but is readily soluble in aqua regia, forming auric chloride, AuCl3. The disulfide is difficultly soluble in ammonium sulfide, but more readily soluble in potassium polysulfide, forming a sulfo salt: Au2S, + K2S, = 2 KAuSs. From this solution hydrochloric acid precipitates a yellowish-brown sulfide: 2 KAuS.2 + 2 H+-2 K+ + H2S + Au2S, (?). From a hot solution, hydrogen sulfide precipitates brown, metallic gold: 8 Au+++ + 3 H2S + 12 H20--30 H+ + 3 SOr + 8 Au. The finely divided metallic gold is soluble in hot potassium or sodium polysulfide, forming a thio salt: 2 Au + K2S4-2 KAUS2. On account of its softness, gold is always alloyed with silver and copper when used for c.<

ISBN: 9781236324108

Analytical chemistry Volume 1 Frederick Pearson Treadwell, Books, Science and Nature, Analytical chemistry Volume 1 Books>Science and Nature, General Books LLC