Caustic Potash Solution

Stress corrosion can arise in plain carbon and low-alloy steels if critical conditions of temperature, concentration and potential in hot alkali solutions are present (see Section 2.3.3). The critical potential range for stress corrosion is shown in Fig. 2-18. This potential range corresponds to the active/passive transition. Theoretically, anodic protection as well as cathodic protection would be possible (see Section 2.4) however, in the active condition, noticeable negligible dissolution of the steel occurs due to the formation of FeO ions. Therefore, the anodic protection method was chosen for protecting a water electrolysis plant operating with caustic potash solution against stress corrosion [30]. The protection current was provided by the electrolytic cells of the plant. 

Boil a few drops of aldehyde with i—2 c.c. of caustic potash solution. The liquid becomes yellow and a brown resinous piecipitate is formed. 

Add a little caustic potash solution. Crystals of potassium oxalate are deposited. The ester is hydrolysed. 

Reaction.—Warm a little of the epichlorhydrin with caustic potash solution. It dissolves, forming glycerol. See Appendix p. 260. 

This compound is heated with caustic potash solution, yielding beta-hydroxy-coumarin. From this body, coumarin is obtained by substituting a halogen atom for the OH group, and then reducing the product in alcoholic solution with zinc-dust. 

Atzkali) n. caustic potash, -lauge) /. caustic potash lye, caustic potash solution. Idsung, /. caustic potash solution, -stuck) n. piece of caustic potash. 

Kali-kugel, /. potash bulb, -lauge, /. potash lye, caustic potash solution, -losung, /. potash solution, -metall, n. (metallic) potassium. -olivenolseife, /. potash olive oil soap, -praparat, n. potash (or potassium) preparation. -reibe,/. (Petro. ) potash series, -roh-salz, n. crude potassium salt, -salpeter, m. 

Oxidation with ammonium persulfate and dilute caustic soda gives bismuth tetroxide, Bi204. The same product can be obtained by using other oxidizing agents such as potassium ferricyanide and concentrated caustic potash solution. 

Cyanogen chloride reacts with caustic soda or caustic potash solution forming the alkah metal cyanide and the oxychloride ... 

Reactions with caustic soda and caustic potash solution yield sodium cyanide and potassium cyanide, respectively ... 

In caustic soda or caustic potash solution, mercury(TI) iodide forms complex salts, Na2Hgl4 and K2Hgl4, respectively. Alkaline solution of this complex in excess potassium hydroxide is known as Nessler s reagent, used to analyze ammonia. The reaction of Nessler s reagent with ammonia may be written as ... 

When heated with dilute caustic potash solution, a yeUow hrown powder of composition Hgl2 3HgO is obtained. 

Black solid density 10.2 g/cm melts at 450°C thermally decomposes insoluble in water, alcohol, acids and aqua regia soluble in caustic potash solution. 

Silane Colorless gas repulsive odor density 1.44 g/L hquefies at -111.8°C freezes at -185°C decomposes slowly in water insoluble in alcohol, ether, chloroform and sdicon tetrachloride soluble in caustic potash solution. 

Silanes do not react with water under normal conditions. In the presence of alkalies base hydrolysis readily occurs. Thus, reactions with caustic potash solution yield potassium silicate with evolution of hydrogen ... 

Normal N 62 pump oil Is to be used to pump basic (alkaline) solutions. Sodium hydroxide and caustic potash solutions should not be pumped In their concentrated form. Ammonia is highly amenable to pumping with the gas ballast valve closed. Alkaline organic media such as methylamlne and dimethylamlne can also be pumped satisfactorily, but with the gas ballast valve open. 

Caustic Arsenic Chloride Caustic Oil of Arsenic Caustic Potash Caustic Potash Solution Caustic Soda Caustic Soda Solution CD-68 Cellosolve Cellosolve Acetate... 

Arsenic Trichloride Arsenic Trichloride Potassium Hydroxide Caustic Potash Solution Sodium Hydroxide Caustic Soda Solution Chlordane... 

CAUSTIC POTASH SOLUTION Potassium Hydroxide Solution, Lye Corrosive Material, II 3 0 1 ... 

Vanadium Subnitride, VgN, is described as a black powder which is not attacked by hydrochloric acid or caustic potash solution. It is soluble in concentrated nitric and sulphuric acids, and evolves ammonia on being heated with solid caustic potash. 

Reaction XXXVI. Condensation of Carbon Tetrachloride with Phenols and simultaneous Hydrolysis (Tiemann-Reimer). (B., 10, 2185.)—This reaction is closely analogous to that of the formation of hydroxy-aldehydes by means of chloroform and caustic alkali (see p. 104). A mixture of a phenol, carbon tetrachloride and caustic soda or caustic potash solution is boiled. Condensation occurs, chiefly in the para-position, but small amounts of the ortho-acids are also formed. The product, after the excess of carbon tetrachloride has been removed, is saturated with carbon dioxide and the unchanged phenol extracted with ether. The hydroxy acids are then precipitated by acidification with hydrochloric acid. 

N.B.—Ether, which is kept in air and light, develops peroxides which are explosive and remain in the residue after distillation. These can usually be removed by shaking with permanganate solution or with silver nitrate and caustic potash solutions. Ether, therefore, should always be distilled from a water bath to avoid heating the residue to a high temperature. 

The presence of unconverted starch may be detected also by treating the dextrin with concentrated caustic potash solution, which gives a clear solution if only soluble starch is present, but a kind of paste if unmodified starch remains. 

Preparation of the Solutions Polarimetric Tests.—100 c.c. of the wine are neutralised in a porcelain dish with caustic potash solution, care being taken not to render the liquid alkaline.1 The alcohol is evaporated off on a water-bath and the residue introduced into a 200 c.c. flask, into which also the dish is rinsed several times with water. A slight excess (about 5 c.c.) of basic lead acetate solution is added, the precipitate formed being allowed to settle and sufficient saturated sodium sulphate solution added, drop by drop, to precipitate the excess of lead. When further addition of the sodium sulphate solution fails to produce a precipitate, the liquid is made up to 200 c.c. with water, shaken, allowed to settle and filtered by decantation through a dry filter. 

Konig s test. 50 c.c. of the wine are neutralised with 10% ammonia (D 0-960), an excess of 5c.c. of the same ammoniabeingaddedandthe liquid boiled gently with about 0-5 gram of defatted white wool until the alcohol and excess of ammonia are expelled. The wool is thoroughly washed with water and heated in a test-tube in a water-bath with 10 c.c. of 10% caustic potash solution until the wool is dissolved. 

The plates are then removed from the cell and the latter, carefully taken from the thermostat o-i c c. of N/io-caustic potash solution is then added from a graduated pipette, the end of which touches the wall of the cell as near as possible to the surface of the liquid. The latter is mixed—care being taken that no bubbles remain adhering to the electrodes—and the cell again placed in the thermostat and a second reading taken at the same temperature as the first. Successive readings are made in the same way after addition of successive tenths of a c c. of the N/io-alkali. 

In a distillation flask with a three-bulbed neck, 50-100 c.c. of the oil are distilled, the last 5 c.c. passing over being collected in a flask and treated, drop by drop, with an equal volume of pure concentrated sulphuric acid, the flask being cooled with water and ice to prevent heating. The liquid is then transferred little by little to a tapped funnel containing 20 c.c. of water and cooled with a stream of water, and extracted with 10 c.c. of pure amyl alcohol. The aqueous acid liquid is poured away and the amyl alcoholic layer washed with a little water and then shaken with 5 c.c. of 20% caustic potash solution. In presence of safrole, the alkaline liquid which separates is coloured green or bluish and, when removed, filtered and acidified with sulphuric acid, it becomes violet-red. 

With Alcohouc Potash. The oil is boiled with alcoholic caustic potash solution this results in the formation and precipitation of potassium chloride, which may easily be identified. 

The part insoluble in ammonium acetate, containing the lead chromate, barium sulphate and clay, is suspended in 50 c.c. of water, treated with 25 c.c. of caustic potash solution (112 grams per litre) and heated to boiling for 10 minutes the lead chromate dissolves, whilst the barium sulphate and clay or kaolin remain undissolved and are collected, calcined and weighed. 

Behaviour towards Potash.—A small quantity of the substance is boiled with about 20% caustic potash solution if the liquid becomes more or less brownish-yellow, humous substances are present (natural or dried umber) if the liquid remains colourless, these are not present (burnt umber). 

Potash Test.—A small quantity of the substance is boiled with 20% caustic potash solution, in which it should largely dissolve, giving a dark brown liquid which, when neutralised with hydrochloric acid, yields a flocculent, brown precipitate. 

A little of the sample is boiled for a few minutes with 10% caustic potash solution, which dissolves animal but not vegetable fibres. 

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