The synthesis of piperine follows from the interaction of piperyl chloride (formed from piperic acid and phosphorus pentachloride) and piperidine (L.
It may be obtained crystalline by fusing the anhydrous chloride with a large excess of potassium hydrogen fluoride or by heating the amorphous variety to redness with an excess of an alkaline chloride.
Cuprous iodide, Cu 2 l 21 is obtained as a white powder, which suffers little alteration on exposure, by the direct union of its components or by mixing solutions of cuprous chloride in hydrochloric acid and potassium iodide; or, with liberation of iodine, by adding potassium iodide to a cupric salt.
Thus the osmotic pressure, or the depression of the freezing point of a solution of potassium chloride should, at extreme dilution, be twice the normal value, but of a solution of sulphuric acid three times that value, since the potassium salt contains two ions and the acid three.
Again, the diazonium chlorides combine with platinic chloride to form difficultly soluble double platinum salts, such as (C 6 H 5 N 2 C1) 2 PtC1 4; similar gold salts, C 6 H,N 2 C1 AuC1 3, are known.
Either they are placed in a leaden cupboard into which the vapour is introduced, or they are dipped for a few seconds in a mixture of one part of chloride of sulphur and forty parts of carbon disulphide or purified light petroleum.
It closely resembles the chloride in being deliquescent, dissolving ferric hydrate, and in yielding basic salts.
His attention was at first divided between two processes - the chemical method of reducing the chloride with potassium, and an electrolytic method of decomposing it with a carbon anode and a platinum cathode, which was simultaneously imagined by himself and R.
Boron and iodine do not combine directly, but gaseous hydriodic acid reacts with amorphous boron to form the iodide, BI 31 which can also be obtained by passing boron chloride and hydriodic acid through a red-hot porcelain tube.
Copper sulphate is readily soluble in water, but insoluble in alcohol; it dissolves in hydrochloric acid with a considerable fall in temperature, cupric chloride being formed.