Caustic-potash sentence example
The corresponding decomposition of a glyceride into an acid and glycerin takes place when the glyceride is distilled in superheated steam, or by boiling in water mixed with a suitable proportion of caustic potash or soda.
These are washed with ammonium chloride until the filtrate is colourless, ignited, fused with caustic potash and nitre, the melt dissolved in water and nitric acid added to the solution until the colour of potassium ruthenate disappears.
The residue is then fused with caustic potash and nitre, dissolved in water, saturated with chlorine and distilled on the water-bath in a current of chlorine.
It is also oxidized when fused with caustic potash and nitre, forming a ruthenate.
Fusion with caustic potash converts it into a mixture of potassium ruthenate and ruthenium sesquioxide, Ru 2 0 3, which is a black, almost insoluble powder.Advertisement
Potassium ruthenate, K2Ru04 H20, obtained by fusion of the metal with caustic potash and nitre, crystallizes in prisms which become covered with a black deposit on exposure to moist air.
When fused with caustic potash it yields phenol and salicylic acid.
On fusion with caustic potash it decomposes with formation of tetrahydroxy-benzophenone, which then breaks up into resorcin and hydroquinone.
A boiling solution of caustic potash hydrolyses it to ammonia and succinic acid.
The beautiful yellow precipitate is little soluble in dilute nitric acid, but soluble in caustic potash.Advertisement
This acid, H 2 Sn0 3, is readily soluble in acids forming stannic salts, and in caustic potash and soda, with the formation of orthostannates.
The former is completely decomposed when fused with caustic potash and the latter by a prolonged boiling with nitric acid.
Of metals not decomposing liquid pure water, only a few dissolve in aqueous caustic potash or soda, with evolution of hydrogen.
Zinc hydroxide, Zn (OH) 2, is prepared as a gelatinous precipitate by adding a solution of any zinc salt to caustic potash.
The best yield of chlorate was obtained when from I to 4% of caustic potash was present.Advertisement
In this process cellulose (in the form of sawdust) is made into a stiff paste with a mixture of strong caustic potash and soda solution and heated in flat iron pans to 20o-250 C. The somewhat dark-coloured mass is lixiviated with a small amount of warm water in order to remove excess of alkali, the residual alkaline oxalates converted into insoluble calcium oxalate by boiling with milk of lime, the lime salt separated, and decomposed by means of sulphuric acid.
But carbolic acid and caustic potash destroy it only after a day or two, consequently they are not a remedy.
Bismuth dioxide, BiO or Bi 2 O 2, is said to be formed by the limited oxidation of the metal, and as a brown precipitate by adding mixed solutions of bismuth and stannous chlorides to a solution of caustic potash.
In the second portion the carbonic acid is driven out by means of a current of hydrogen, collected over mercury and absorbed by caustic potash.
On fusion with caustic potash it yields potassium osmiate.Advertisement
It forms a grey brittle mass, having a conchoidal fracture; it is very deliquescent, combining very energetically with water to form caustic potash.
Glass and (to a less extent) porcelain are attacked by caustic potash ley, slowly in the cold, more readily on boiling.
All commercial caustic potash is contaminated with excess of water (over and above that in the KHO) and with potassium carbonate and chloride; sulphate, as a rule, is absent.
The salt is soluble in water, but insoluble in caustic potash of sp. gr.
It decomposes in moist air, or with water, giving caustic potash and ammonia, in the latter case with considerable evolution of heat.Advertisement
From caustic potash are made (I) Potassii Permanganas, dose 1 to 3 grs., used in preparing Liquor Potassii Permanganatis, a I A solution, dose 2 to 4 drs.
Poisoning by caustic potash may take place or poisoning by pearl ash containing caustic potash.
The metallic cyanides may be detected by adding ferrous sulphate, ferric chloride, and hydrochloric acid to their solution, when a precipitate of Prussian blue is produced; if the original solution contains free acid it must be neutralized by caustic potash before the reagents are added.
The amount of hydrocyanic acid in a solution may be determined by adding excess of caustic potash and a small quantity of an alkaline chloride, and running into the dilute solution standard silver nitrate until a faint permanent turbidity (of silver chloride) is produced, that is, until the reaction, 2KNC+AgNO 3 = KAg(NC) 2 - -KNO 3, is completed.
The substances used as tests in these reactions are caustic potash and calcium hypochlorite; the former being the substance dissolved in an equal weight of water and the latter a saturated extract of bleaching powder in water.
A yellow colour with caustic potash solution is produced not only by atranoric acid but also by evernic acid, thamnolic acid, &c. Again in the case of Xanthoria parietina vulpinic acid is only to be found in young thalli growing on sandstone; in older forms or in those growing on another substratum it is not to be detected.
When prepared by the action of metals on bases, zinc or aluminium and caustic soda or caustic potash are used.
Hydrogen may also be obtained by the action of zinc on ammonium salts (the nitrate excepted) (Lorin, Comptes rendus, 1865, 60, p. 745) and by heating the alkali formates or oxalates with caustic potash or soda, Na2C204+2NaOH = H 2 +2Na 2 CO 3.
Moringa-tannin or maclurin, C1,H1006 H20, found in Morus tinctoria, hydrolyses on fusion with caustic potash to phloroglucin and protocatechuic acid.
Calcium chloride gives a white precipitate of calcium tartrate in neutral solutions, the precipitate being soluble in cold solutions of caustic potash but re-precipitated on boiling.
The amorphous variety may be obtained from the crystalline form by dissolving it in caustic potash or soda or in solutions of alkaline sulphides, and precipitating the hot solution by dilute sulphuric acid.
Many ortho and, para-compounds of the aromatic series (for example, the brom-phenols, benzene para-disulphonic acid) also yield resorcin on fusion with caustic potash.
The oxypyridines may be prepared by distilling the corresponding oxypyridine carboxylic acids with lime, or by fusing the pyridine carboxylic acids with caustic potash.
In 1810 Gomez of Lisbon obtained a mixture of alkaloids which he named cinchonino, by treating an alcoholic extract of the bark with water and then adding a solution of caustic potash.
On boiling with caustic potash they evolve hydrogen, yielding a phosphate.
Lepidine(y-methylquinoline) was first obtained by distilling cinchonine with caustic potash.
Euler (Ber., 97, 30, 1989) by distilling the addition compound of methyl iodide and 2 3 5-trimethylpyrollidine with caustic potash.
It may also be prepared as a black velvety powder which readily takes up oxygen from the air by adding ferrous oxalate to boiling caustic potash.
Fritzsche showed that by treating indigo with caustic potash it yielded an oil, which he named aniline, from the specific name of one of the indigo-yielding plants, Indigofera anil, anil being derived from the Sanskrit nila, dark-blue, and nila, the indigo plant.
Potassium chromate, K2Cr04, may be prepared by neutralizing a solution of potassium bichromate with potassium carbonate or with caustic potash.
Somewhat later, they found that it could be prepared from diazobenzene imide, provided a nitro group were present in the ortho or para position to the diazo group. The para-nitro compound is dropped slowly into a cold solution of one part of caustic potash in ten parts of absolute alcohol; the solution becomes dark red in colour and is then warmed for two days on the water bath.
Care was required when doing this, as the liquid electrolyte contained caustic potash which would attack the hands or clothes.
The hydroxide, Ir(OH) 3, may be obtained by the addition of caustic potash to iridium sodium chloride, the mixture being then heated with alcohol.
The corresponding hydroxide, Ir(OH) 4, is formed when potassium iridate is boiled with ammonium chloride, or when the tetrachloride is boiled with caustic potash or sodium carbonate.
Cobaltous hydroxide, Co(OH) 21 is formed when a cobaltous salt is precipitated by caustic potash in the absence of air.