Hydrate of potassa

Tor use in the laboratory, hydrate of potassa, prepared as above, is treated with rectified spirit of wine in a stoppered bottle. The solution is allowed to deposit, decanted and evaporated in a silver dish, until fumes coase to be evolved, adding from time to time during the evaporation some water to prevent blacken-... 

To obtain it perfectly free from alumina, Schubert directs hydrate of potassa to be prepared by decomposing the sulphate of that base by means of hydrate of baryta. A solution of this latter salt is added to one of pure sulphate of potassa in exactly sufficient quantity to effect decomposition. Tho decanted solution is then evaporated as previously described. 

According to Fuchs, hydrate of potassa may bo economically obtained from certain varieties of felspar and foam mica. For this purpose the minerals are calcined with lime, then left for some time in contact with water, and the solution is afterwards filtered and evaporated. From his statement it appears that nineteen per cent, of potassa may be obtained from felspar, and fifteen per cent, from mica. 

Hydrate of potassa is a white opaque mass, which, when broken, exhibits a crystalline fracture. Its specific gravity is 17. It fuses at a low-red heat, and at a white heat volatilizes unaltered. Its teste is acrid and corrosive. It has a strongly alkaline reaction, a rapid Bolvent action on animal matters, and is the most powerful base known. Its formula is KO, II0 it is very deliquescent, very soluble in water, and crystal-lizable. The following table, deduced from Dalton s experiments, shows the quantity of anhydrous potassa contained in solutions of various densities —... 

The impurities most frequently met with in solution of and solid hydrate of potassa are carbonate of lime oxide of iron, silica, alumina, carbonate and sulphate of potassa, and chloride of potassium. > Carbonic acid is indicated by effervescence on the addition of an acid. Carbonate of lime and oxide of iron remain insoluble when the salt is treated with water. Silicic acid and... 

Synonyms Caustic potash, Caustic potassa, Hydrate of potassa, Potassium hydrate. Appearance White, deliquescent lumps or sticks. 

The crude oil was carefully mixed with hydrate of potassa and a solution of chloride of iron by strong agitation and then submitted to distillation. The whole of the oil passed over with the water, and perfectly free from prussic acid. By means of a tube, it was separated from the water, and redistilled in a dry apparatus over freshly burned, powdered chalk. 

The manner of its purification shews that it is not decomposed or changed by anhydrous alkali, but to the hydrated, its behavior is different. Heated with the hydrate of potassa, apart from the air, it forms benzoate of potassa and evolves pure hydrogen gas. 

If the oil be introduced into solution of hydrate of potassa in water, or into alcohol saturated with ammoniacal gas, it is immediately dissolved, and if the air be wholly excluded, a benzoate appears which when potassa is employed, is soon deposited in large shining lamellar crystals. By the addition of water which dissolves... 

The formation of benzoate of potassa from the oil, when the latter is heated with hydrate of potassa, depends upon the decomposition of the water in the hydrate, whereby the oil takes one atom of oxygen, while hydrogen escapes in the form of gas. 

By neglecting perfectly to dry the ammonia over burnt lime or hydrate of potassa, a corresponding mass of benzoate of ammonia is formed, by the action of the moist gas upon the chlorobenzoyl, and the same proportion of the new body is lost. 

We in vain endeavored to reconvert benzoin into hydrobenzoyl. Fused with hydrate of potassa, it changes like the oil into benzoic acid, with the evolution of hydrogen. But again it differs from the oil, in its behavior with a solution of potassa in alcohol. It is dissolved in the alkaline solution with a purple color, and presently the whole congeals to a mass of fine, foliated crystals. With water these form a milky fluid, firom which by cooling after it has been heated, thick flakes of needle-form crystals are deposited, which are unchanged benzoin. 

Potassium hydroxide 101, 3976 KOK Caustic potash, potassa hydrated oxide oxide of potassa hydrate of potassa potassa hydrate potasslc hydrate potassium hydroxide potassa stock lye. 

AiJiydrous Potassa. This is a volatile, fusible, white substance, intensely corrosive, and passing into tho hydrate of potassa when moistened with water. It is obtained by the combustion of potassium in hot dry air. 

To Obtain Light Carburetted Hydrogen. When 2 parts crystallized acetate of soda, 2 parts dry hydrate of potassa, and 3 parts powdered quicklime, are strongly heated in a flask or retort, this gas is abundantly evolved, and may be collected over water. See Ko. 4031.)... 

Oxide of Silver. Dissolve 2 parts nitrate of f ilver, and I part hydrate of potassa-, each separatelr, in aistilled water mix the solution, and, alter frequent agitation during an hour, collect and wash the precipitate, and dry it by a gentle heat in the shade. This is more strictlv the protoxide of silver, and is in the fonn of a pale brown powder. 

Hydrate of Potaasa. This is also known under the name of caustic potash. Liquor of potassa, 1 gallon evaporate in a clean iron vessel over tiie fire until the ebullition being finished, the hydrate of potassa liqaefios poor this into proper moulds. A pue greyi or bluish sohd, very soluble in water imd alcohol. It should bo totally soluble in alcohol. Its solution should scarcely affected hy the nitrates of baryta and silver. It is chiefly used as a caustic, and in chemistry. ( Cooley,)... 

Potassa with Lime. Kub together, in a warm mortar, 1 ounce each of hydrate of potassa and quicklime, and keep the powder from the air in a well-stopped bottle. This is a caustic, but less manageable than either nitrate of silver (lunar caustic) or hydrate of potassa (caa.stio potash.)... 

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