On the application of the conversion of chlorates and nitrates into chlorides, and of chlorides into nitrates, to the determination of several equivalent numbers / by Frederick Penny.

  • Frederick Penny
Date:
1839
Catalogue details

Licence: Public Domain Mark

Credit: On the application of the conversion of chlorates and nitrates into chlorides, and of chlorides into nitrates, to the determination of several equivalent numbers / by Frederick Penny. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    in the process, there are several others to be observed to ensure success. As soon as the action commences, the flask should be removed from the sand bath, and the decomposition be permitted to continue without heat. When the action slackens, the flask may be returned to the sand bath, and so on, to and from the source of heat, until it is so gentle that no lateral spirting can be feared. The adaptation of a receiver throughout the whole of these operations must be strictly attended to; for despite every care, a minute portion of the solution will sometimes be ejected during the evaporation. This circumstance happened in three of the experiments I shall mention presently. In one case the weight was *003 of a grain, in another *008, and in a third ‘005. The receiver flask should not be detached from the other even while removing them to and from the sand bath, nor in fact until the resulting chloride is nearly dry, as slight action continues during the greater part of the evaporation. 31. Very particular attention was paid to the purity of the salt employed. It was prepared from the common purified nitre of the shops, by four repeated crystallizations from distilled water. After each crystallization the salt was dried, and finely powdered, and this powder well washed with distilled water. When finally washed and dried, 200 grs. were fused in a platina crucible. They yielded a perfectly colourless mass, soluble in water without a trace of insoluble matter, and the solution was not affected by nitrate of silver, chloride of barium, oxalate of ammonia, or hydrosulphuret of ammonia. It was dried by careful fusion. The resulting chloride was dried in the same way as the chloride from chlorate. From one to two fluid ounces of hydro- chloric acid are sufficient for the quantities of nitrate employed. In adding this acid one important practical circumstance must be observed, namely to add it in two successive portions, and to expel the first quantity previously to the addition of the second. This method is necessary from the small size of the flask, compared with the bulk of fluid. The less the quantity of fluid in the flask at one time, the less chance of loss by spirting. 32. I obtained, in seven experiments, the following very satisfactory results : Nitrate. Chloride. Nitrate. Chloride. 60-290 . . . 44-452 . . . . 100 . . . . 73-731 58-230 . . . 42.927 . . . . 100 . . . . 73-726 63-040 . . • 46-479 . . . . 100 . . . . 73-730 51-514 . . • • 37-978 . . . . 100 . . . . 73-724 56-036 . . • 41-315 . . . . 100 . . . . 73-730 80-517 • • • 59-362 . . . . 100 . . . . 73726 78-643 . . • • 57-983 . . . . 100 . . . . 73-730 mean will be as 100 of nitrate to 73'728 chloride, or 100 of chloride to 135-634 nitrate.
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