REACTIONS IN THE DRY WAY Hra
The borax or sodium metaphosphate bead, containing a small amount of an iron salt, is yellow while hot and colorless when cold after being heated in the oxidizing flame, and pale green after being heated in the reducing flame. When strongly saturated, however, the bead obtained with the oxidizing flame is brown while hot, yellow when cold and after heating in the reducing flame it becomes bottle-green. Heated on charcoal with soda before the blowpipe, all iron com pounds leave a gray particle...
REACTIONS IN THE DRY WAY Kdb
All ammonium salts are relatively unstable compounds, the degree of stability depending, in general, upon the strength of the acid which is combined with the ammonium. The carbonate decomposes appreciably at ordinary temperatures and when exposed to the air gradually disappears as ammonia, carbon dioxide and water. Heating in a closed tube causes the decomposition of all ammonium salts and either ammonia or some other volatile nitrogen compound escapes. If the acid is volatile at the...
Reactions In The Wet Way
Potassium forms very few salts that are difficultly soluble in water. The chloroplatinate, acid tartrate, and perchlorate are the least soluble, and are consequently used in the detection of potassium. 1. Chloroplatinic Acid, H2 PtCl6 , gives in concentrated solutions of the chloride a yellow precipitate of potassium chloroplatinate, which consists of small regular octahedra visible with a magnify-ing-glass . In case the potassium solution is not very concentrated, no precipitation may appear...
MnHHMnH T CoHHCoH T
4. Potassium Ferricyanide and Ferric Chloride. If a trace of potassium ferricyanide is added to a very dilate and nearly neutral solution of ferric chloride, so that the solution appears a distinct yellow, and a nearly neutral solution of hydrogen peroxide is then added, the mixture will soon assume a green tint, and finally, on standing, Prussian blue will separate out. The potassium ferricyanide is reduced by the hydrogen peroxide to potassium ferrocyanide, which forms Prussian blue with the...
REACTIONS IN THE WET WAY Rdb
1. Ammonia produces a gelatinous precipitate of aluminium hydroxide, which is somewhat soluble in water, but insoluble in the presence of ammonium salts The property which the aluminium hydroxide shows of partly dissolving in water, is common to all colloidal substances cf. p. 59 . When dissolved they are sometimes said to exist in the hydrosole condition and when precipitated as hydrogele. The hydrosole form of aluminium hydroxide can be converted into hydrogele by the addition of salts,...
REACTIONS IN THE WET WAY Fgj
1. Ammonia and Ammonium Carbonate same as with calcium and strontium. 2. Ammonium Oxalate same as with calcium and strontium, except that the barium oxalate formed is more soluble in water 1 gm. dissolves in 2.6 liters of cold water , and is readily dissolved by hot dilute acetic acid. 3. Phosphates of the Alkalies same as with calcium. 4. Chromates of the Alkalies produce in neutral solutions of barium salts a yellow precipitate of barium chromate thus differing from calcium and strontium ,...
Reactions In The Dry Way
Potassium compounds color the non-luminous flame violet. The presence of very small amounts of sodium obscures the violet color, but if the flame is viewed through cobalt glass or indigo solution, the reddish-violet potassium rays pass through, while the yellow sodium rays are completely absorbed. Flame Spectrum. Potassium gives a characteristic flame spectrum. A double red line, 769.9 mm and 766.5 mm appearing as a single line with weaker dispersion , and a faint violet line, 404.4 mm, appear...
Preparation Of Sodium Cobaltinitrite
Dissolve 150 gms. of sodium nitrite in 150 cc. of hot water and allow the solution to cool to about 40 , which will cause the deposition of some sodium nitrite crystals. Add 50 gms. of cobalt nitrate crystals, stir rapidly and add 50 cc. of 50 per cent acetic acid in small portions stopper the flask and shake vigorously. Pass a rapid stream of air through the liquid and then allow it to stand quietly over night. In the morning, more or less brown precipitate will be found on the bottom of the...
Info Muo
The table of oxidation potentials will help to explain many of the reactions used in analytical chemistry. All the metals above hydrogen will replace the hydrogen of dilute acids those below hydrogen will not do so as a rule. The oxidation of copper to cuprous ions, however, corresponds to an oxidation potential of 0.17 volt. When the acid is very concentrated and the cuprous solution very dilute, the oxidation potential of the copper to univalent copper will be above that of hydrogen and...
Reactions In The Wet Way 1
1. Potassium Pyroantimonate, K2H2Sb207, produces in neutral or weakly alkaline solutions of sodium salts a heavy, white, crystalline precipitate, which is formed more quickly by rubbing the sides of the vessel with a glass rod The test must not be made in an acid solution, for in that case an amorphous precipitate of pyroantimonic acid will be formed Furthermore, no other metals than the alkalies should be present, because they also cause precipitates amorphous ones for the most part. 2....
i OtL x
By adding an equivalent weight of sodium acetate, therefore, the ionization of 0.1 N acetic acid is changed from 1.3 per cent to 0.02 per cent. The effect of ammonium salt upon the ionization of ammonium hydroxide is similar. The table on page 22 gives the solubility product of ferric hydroxide as 1.1 X10 36 and that of magnesium hydroxide as 3.4 x10-11. As the cube of the OH concentration is taken in computing the solubility product of ferric hydroxide and only the square of this concentration...
Hcns
Dection of HCNS in Presence of Halogen and Cyanide 325 Detection of HCNS, H4 Fe CN 6 and H3 Fe CN 6 327 Cobalticyanic Nitrous Acetic Tartaric Pyrophosphoric Phosphoric Arsenious Arsenic