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Preparation of bicarbonate of potash
408 Progress of Practical & Theoretical Mechanics ~. Chemist~'zj. And as to what concerns the mula, we find 1 vol. 9~ vol. 2 vol.
density, calculated according to the same forof chrome of chlorine of oxygen
S.8811 4.~890 2.92078 10.9809 ~---5.49
But here each atom of the compouml represents only two volumes of vapour. This body may therefore be regarded as a distinct acid, which might be named chloro.oxi-chromic acid. Recollecting that the perchloride of chrome does not exist ill an isolated state, that analogous compounds are only produced by acids, which for one atom of radical, contain three atoms of oxygen, which are isomorphous with each other, anti which n~av all be expressed after fl~e hypothesis of M. Persoz, by the formula R 02 "I- O, iu taking into consideration the facility with which this b~tly is decomposed when brought into contact with other bodie%antlits little stabilily;thi~ manner of regarding the constitution of this body, which explains its various actions~ offi.'rs the appearance of much probability. Lurid. and Edin. Plfilo8, Mag,
Preparation of Bicarbonate of Potash. By P"oL ~,V(~znLEI¢. Carbonate of potash, both in the dry state and in solution, cmnbines very .slowly with the second equivalent of carbonic acid to f,rm the bicarbonate of potash. By means of charcoal in a finely divided state the combinatiotl may be made to take place very easily. It can be I)erformetl in the following manner: bitartrate of potash is tu be heated in a covered crucible, the burnt mass to be moistened with water, put into a receiver, and carbonic acid passed through it. The absorption takes place with such rapidity ti~at the mass becomes strongly heated, '~+omuch so that it is necessary to surround the receiver with cold water to In'eve/It the reconversion of it into carbonate of potash. The saturatim~ is Cmnldete when it ceases to z,ive out heat. It is then dissolved in the smallest possible quantity of watt," at the tetnperature of 100 ° to l~0 ° Fahr.; upon the cooling ol the tiltered solutiotb the e,reater part of the bicarbonate separates io fine crystals.--Pog~en. dorjf's dnnals. Lond.&Ed. v~,il,,~,~',~, Prq~aralion of Protoxide ~f Tin. Owing to the great difficulty of preparing protoxide of tin according to the directions generallygiveo in chemical works~ 1 was led to make some experiments on ttae subject. I find the fidlowing process to be Ihat which yiehls the purest oxide. P r e p a r e a solutiml of protnchhwide ot tin by dissolving the metal in hydrochloric acid, taking care always to have a g r e a t excess of the metal; the solution is then evaporated to drynes%together with a lump of tin to prevent the formation of perchhwide, The tin is then separated, and the chloride weighed, and rubbed in a mortar with its equivalent, or rather more, of crystallized carbonate of soda; the mixture soon becomes fluid; it is then put inte an evaporati~g dish and heated on the sand-batlh frequently stirring, till it becomes thorou_~hly black; it is then removed, and well washed with boiiine,,~water~ fiitered~and dried at a gentle
density, calculated according to the same forof chrome of chlorine of oxygen
S.8811 4.~890 2.92078 10.9809 ~---5.49
But here each atom of the compouml represents only two volumes of vapour. This body may therefore be regarded as a distinct acid, which might be named chloro.oxi-chromic acid. Recollecting that the perchloride of chrome does not exist ill an isolated state, that analogous compounds are only produced by acids, which for one atom of radical, contain three atoms of oxygen, which are isomorphous with each other, anti which n~av all be expressed after fl~e hypothesis of M. Persoz, by the formula R 02 "I- O, iu taking into consideration the facility with which this b~tly is decomposed when brought into contact with other bodie%antlits little stabilily;thi~ manner of regarding the constitution of this body, which explains its various actions~ offi.'rs the appearance of much probability. Lurid. and Edin. Plfilo8, Mag,
Preparation of Bicarbonate of Potash. By P"oL ~,V(~znLEI¢. Carbonate of potash, both in the dry state and in solution, cmnbines very .slowly with the second equivalent of carbonic acid to f,rm the bicarbonate of potash. By means of charcoal in a finely divided state the combinatiotl may be made to take place very easily. It can be I)erformetl in the following manner: bitartrate of potash is tu be heated in a covered crucible, the burnt mass to be moistened with water, put into a receiver, and carbonic acid passed through it. The absorption takes place with such rapidity ti~at the mass becomes strongly heated, '~+omuch so that it is necessary to surround the receiver with cold water to In'eve/It the reconversion of it into carbonate of potash. The saturatim~ is Cmnldete when it ceases to z,ive out heat. It is then dissolved in the smallest possible quantity of watt," at the tetnperature of 100 ° to l~0 ° Fahr.; upon the cooling ol the tiltered solutiotb the e,reater part of the bicarbonate separates io fine crystals.--Pog~en. dorjf's dnnals. Lond.&Ed. v~,il,,~,~',~, Prq~aralion of Protoxide ~f Tin. Owing to the great difficulty of preparing protoxide of tin according to the directions generallygiveo in chemical works~ 1 was led to make some experiments on ttae subject. I find the fidlowing process to be Ihat which yiehls the purest oxide. P r e p a r e a solutiml of protnchhwide ot tin by dissolving the metal in hydrochloric acid, taking care always to have a g r e a t excess of the metal; the solution is then evaporated to drynes%together with a lump of tin to prevent the formation of perchhwide, The tin is then separated, and the chloride weighed, and rubbed in a mortar with its equivalent, or rather more, of crystallized carbonate of soda; the mixture soon becomes fluid; it is then put inte an evaporati~g dish and heated on the sand-batlh frequently stirring, till it becomes thorou_~hly black; it is then removed, and well washed with boiiine,,~water~ fiitered~and dried at a gentle