PATRICK H. WOODSAND LEONED. COCKERELL
1334
I7ol. so
sonably explained in terms of a Gal [GaIIIC14]formulation.
Two additional significant facts came to light. First, as is seen from Table 11, the chlorine: gallium atomic ratio in the benzene solution after TABLE I1 precipitation was three. within experimental error, THEA c r r o ~OF HzS O N GaClz I N BEXZEXE indicating that the gallium remaining was in the Atomic ratin G a in soln. C1.Ga form of the trichloride. ( I t was noted in the ExI'orniula nf starting Ga in solid remaining material Predicted FOUtld in s o h perimental section t h a t appreciable chlorine was GaCll.00 1 . 00 0.97 3.03 evolved as hydrogen chloride during precipitation. (;a CL .w 1.04 1.05 3.03 Moreover, as will be seen below, the precipitate GaCln.lo 1.22 1.24 2 95 contained chloride.) Second, only the precipitate GaCl2.14 1.33 1.25 3.00 possessed reducing power toward ammoniacal sil0dCiz.li 1.25 1.05 2.99 ver nitrate. Both these observations held even in GaCl"?.oj 1.11 1.01 .. situations where the precipitate contained more gallium than that expected froin the formula of the a This material was prepared by the method described in reference 4a. starting compound. The sulfide precipitate could not be characterized In a majority of the precipitations the ratio of as a definite compound. The gallium content gallium iii the solid to that remaining in the benzene solution was close to the ratio expected from ranged from 33.4 to 51.35%; sulfide from 13.1 to the formula of the starting material, on the as- 18.6yo;and chloride from 13.2 to 20.0yo. That sumption t h a t the compound contained both Ga+' the chloride was held quite firmly in the precipitate and [GaC14]- and t h a t the + l gallium was pre- was demonstrated by the fact that neither extraccipitated. This point is brought out in Table 11. tion with benzene nor heating in vacuo to about In a number of cases the quantity of gallium in the 200° altered its content significantly. Acknowledgment.-The authors are indebted to solid exceeded appreciably t h a t predicted from the formula of starting material. N o explanation, be- the Atomic Energy Commission for a grant in s u p vond the possibility of coprecipitation, is offered port of this investig;I t'ion. for this. ~~
[C)ONTRIBC r I O N FROX THE CHEMISTRY I ) E P A R I V E N r O F BAYLOR
UNIVERbIIY]
Anion Exchange of Titanium(1V) in Hydrofluoric Acid B Y PATRICK H. WOODS'AXD LEONED. COCKERELL RECEIVEDAUGUST22. 1957 The method of Fronaeus is uscd to show the existence of anionic fluoride cornplcxes of titaniuin wlicti tlic inetul is dismlvecl in hydrofluoric acid. The color and oxidation state of the product has also beer1 studied.
Introduction Investigators reporting on the dissolution of titanium in hydrofluoric acid disagree as t o the nature and color of the product formed Glatzel? suggests the formation of TiF4, whereas Straunianis3 indicates t h a t the dissolution proceeds according t o the equation 2Ti
+ 6HF --+ 2TiF3 f 3H2
The color of the resulting solution is said to be purple? by some investigators and green3by others. In strongly acid solutions (pH < 2) the existence of the TiO++ ion usually is As far hack as 1908' the existence of TiF6= ion has been suggested. More recently,* the failure to extract titanium salt with ether strongly suggests the pos: 1 ) Taken from a thesis presented by Patrick H. Woods in partial tuliillment of requirements for the Doctor a f Philosophy degree E Glatzel. B e y . . 9 , 1829 (1870). > f , I? Strnurnanis and P. C. Chen. J E : l ~ c t v o c l i 0 i .~S o r , , 98, 231
sibility of an ionic pruduct. If anionic coniplexes are formed, their existence can be shown by the method outlined by F r o n a e ~ s . The ~ purpose of the present investigation was to determine the color, oxidation state and nature of the product formed by the dissolution of titanium in hydrofluoric acid. Experimental Materials.-Reagent grdde chemicals were uscd througliout the investigation. Titanium metal (purified by iodide method) \vas obtained from the Fisher Scientific Co. Purity is better than 99.9cj-i.10 Atnberlite IR.l-400, a strongly basic quaternary :~niinoriiurn type resin, was converted to the fluoride fori11 with concentrated solutions of potassium fluoride. I t was washed until the effluent would no longer give the zircoiiiunalizariii lake test for fluoride," backwashed, column dried :tiid finally air-dried before use. Its moisture content (18.54'?,) and ion capacity (1.4i2 nieq./g.) were determined b y accepted techtiiques.12 Preparation of Solutions.-The stock solution was iiiaclc i i i a polyethylene bottle by dissolving titanium metal in hydrofluoric x i t l . \\7ieti titanium metal was dissolvc.tl it1
(4) I1 J ICtncleu.. i n "k'luc,rinc Cilvrlliitry." ~\rademic b'rws, Inc., N e w Y o r k , S . U..Chaiitcr 1 , 11 i ( i ( 5 , f < I< Schvficr and IC \ I Iianimakci. ' i ' i i i s J O ~ . K U, ~7I2 , 2>7.+> IC E Kleiner, A k o d . .Y,li'L' S.S..? I< , I u Y t O / ~ T / I ~: ~.\-C I Khiiu , 2 6 , l0!> (1!33lj. ( 7 ' J A Schaeffer, THISJOVRX.%I. 30, Isti? [1!JUS) ( 8 ' 5 Kttahara, Repis S c i . Kisrnrri: Iiisl. ( J o p u , ~ )2, 6 , l(i2 [1919).
Krvi
7'idslu., 65, 1 (1953).
l ~ m d l i o o k < i f Clicn~i.Lry," Ilxn
