ACTION OF AMMONIUIl CHLORIDE ON CERTAIN CHLORIDES. P A R T I.
ACTION OK METALLIC CHLORIDES. BY
Received May 17, ,904
THEstudy of the action of ammonium chloride on phosphorus pentachloride, when the two bodies are heated together in a sealed tube, was fruitful in results, leading, as it did, to the discovery, by H. N. Stokes,l of a whole series of polymeric chloronitrides of phosphorus, in addition to the one previously known. I t is, therefore, rather strange to note that the allied study of the behavior of other chlorides when similarly treated with sal ammoniac has seemingly been entirely neglected. The present communication is the first contribution t o a general research on the action of ammonium chloride on polychlorides, a problem with which I have been grappling, off and on, during the last four or five years. ACTION OF X I I h l O N I U M CHLORIDE O N ANTIIIONY PENTACHLO-
Antimony chloride being the nearest accessible analogue of phosphorus pentachloride, it was first taken up. T h e expectation was, judging by analogy, that antimony pentachloride and sal ammoniac might react as follows: SbCl, NH,Cl = SbNCl, 4HC1. Accordingly in the first experiments the two substances were digested in equimolecular proportions. On sealing them in tubes and heating, no change was observed until the temperature reached about 200' when the liquid began t o diminish and the solid to increase in quantity. If the temperature is not allowed to rise above 2 0 o 0 - 2 1 j 0 , the process of solidification may take thirty to forty hours, if I O to I j grams of antimonic chloride are digested with corresponding amounts of ammonium chloride. T h e total contents will become solid in ten t o twelve hours at 230°-2j00. T h e change of the physical state is not accompanied by evolutior of hydrogen chloride. Obviously we have here a case of formation of a double sslt. Under favorable conditions of digestion (2joo-27o0)this salt appears as a uniform, compact white mass (with a yellow tinge due probably to impurities), granular in .ct r uc t u re,
A m . C h e m . 1 , 19, 782
PETER F I R E M A S .
S o t before the temperature reaches 3jo' arc. consiclerahie quantities of hydrogen chloride g i \ w ofi aiid the evolution cf gas ioon slackens even at that temperature. ( h l y hetn-een 350' antl 4oai, and preferably nearer to the latter. a comparatively rapid progress of the reaction can !,e iiisurecl. It \vas soon learned that the rcactioii did not take place in the sense indicated by the abo1.e equation : considerably less hydrogen ch lo r i tl e than required i 11 acco rt 1ance the re I\- i t li \v as e vo lv ed and in tlie reac t ion pro tluc t much an timon!. :rich lo ride \vas found. In the earlier esperiinents the digestion \vas stopped when the evolution of gas became very s l o ~ ani1 . since the highest teinperatures \\-Iiich could be attained \vith the furnace then wet1 were beloiv 3;0", the reaction ( i n the light of subsequent esperience) had not been brought to a finish. The consequence \\-as that on tlistilling ofi the antimonioiis chloritlc 2. residue cnntainiiig antimony, nitrogen a n t l chlorine \vas o1itai:ietl. a residue \vhich, a s found later, disappears it' the digestion i b carried on until tlie reaction is completed. As it \vas, the residue itiiiiecccsad!- complicated matters. .And the difficulty \\.as oiil!. o y e r come after an alliec! study of the action of phosp!ioiiium iodide on antimony pentachloride' had been completed 111Ernestine Fireman and the writer. In that case \\-e found that tlic follon-ing reaction takes place : 3S!iC'l., 3€'H,I = 2SbC1:. 4 S b I ; qHC1, + 1":; + ~
I t suggested itself that between antimony pentachloride aiid ammoniiim chloritle, an31ogoiisl!., this reaction midit take place :
iSbC1, 3SH,C1= ?SbCI,, SHCl XH,CI+ S,. or simpler: 3SbC1, + 2SH,C1 = 3SbCl., SHC1 S,.
Sei\- experiments at higher temperatures soon proved the reaction to proceed as represented by these equations. ( ) f the numero'us esperiments, a somen-hat detailed description will be given cnly of the last one, which was made with two tubes. One tube ( I ) received 13.1 grams ( 3 tiiols.) of antimony pentachloride and 1.j7 grams ( 2 rnols. j of ammonium chloride, and another (11) 15.2 grams ( I mol.) of the former and 2.73 grams ( I mol.) of the latter body. On heating the sealed tubes fro'm 1
A m . Chrni. f., 30, I
I ~ .
ACTION OF AMMONIUM CHLORIDE.
ten to tweive hours at 380"-340', tube I lost 1.63 grams and tube I1 1.73 grams of gaseous products. T h e contents of the tubes became solid. Further digestion for from seventeen to eighteen hours a t 38o0-4o5O caused tube I to lose 1.37 grams and tube I1 1.33 grams by escaping gases. The somewhat softened solid mass of the tubes foamed up as the gases rushed out. After renewed heating for twenty-two hours at 38oo-41o0the losses of tubes 1 and I1 were 1.51 and 2.j8 grams, respectively. The foaming in the latter tube was very violent, causing the throwing out of a slight amount of the solid product. Further digestion for fcrty hours at the same temperature occasioned only the losses 0.05 and 0.1gram. The contents of t h e tubes were now a water-clear mass consisting of prismatic crystals with pyramidic base. The total loss of tube I was 4.56 grams instead of 4.69 grams, as calculated for hydrogen chloride and nitrogen according to the above equation; that of tube 11, 5.6j instead of 5.44 grams. The excessive loss in the latter tube was due, as indicated above. to some of the product having been thrown out by the outrushing gases. It will perhaps not be superfluous to give the data of another experiment in which 15.5 grams (I mol.) of antimonic chloride and 2.79 grams (I mol.) of sal ammoniac were used. On heating until no more gases were evolved the total loss was 5.49 grams instead of j . s j grams (theory). The crystalline residue in the tubes was easily identified as antimonious chloride by its ready fusibility and by its boilingpoint. The contents of tube I (without excess of ammonium chloride) distilled almost entirely at 218' (boiling-point of the trichloride of antimonv) and that of tube I1 (with excess of animonium chloride) passed over for the most part a t 218O,but in part, towards the end, at up to 230°,leaving a small residue identified 3s sal ammoniac. To ascertain whether the gaseous product actually contains nitrogen as well as hvdrochloric acid, the evolved gases were in one experiment collected and examined, the tube having been, after digestion, opened under water, after the procedure of Stade1.l I n that case the tube (of about 50 cc. capacity) with the reacting bodies was heated for some time and then cooled and opened as usual; these operations were repeated until about 3 1
A n n . Chcm. (Liebig), 195, xgo
PETER F I R E U A S ,
grams of the gases escaped. ;ifter the most of the air had thus been swept out of the tube the latter \vas once m w e heated. O n cooling, the tube \vas immersed in a 12-gallon jar filled with water. The tip of thc tube pointing to the c!~lincltrr \vas tlxn filed i n under the water until the gas liubb!es began to gently break through T h e discharge of the gases lasted more than ten minutes. The hydrcchloric acid was absorbed 1;). the \vater in the jar while in the cylinder collected I 18 cc. (ret1uct.d to normal temperatureandpress u r e ) of a gas not absorhecl b!- \\.ater. The acitl required 41 cc. of normal potash for neutralization, hence amounting to I .6148 grams, while the I 16 cc. of nitrogen (allon.ing 2 cc. for admixed a i r ) weighed 0.~457 gram. The ratio of 1.6148:0 . r 4 j is ~ equal to I 1.1. while the ratio of hyclrochloric acitl to nitropeii, according to the above equations, is 10.4. These figures, though very rough, accord \vel1 with the sense of the reaction in question. Thus the equation 3SbCI,-C 2SH4C1 = 3SbCI,, $- 8HC1+ S, accu ra t elr. rep r esen t s the react ion bet ween m t irnoii!. pent achl o ride m d ammcnium ch1oride.l iI.
. \ C T I O S O F A l I N O S I K l f C H M R I D E O S T I S TETRA