Spectrophotometric and Radiochemical Investigation of the Interaction Between the Oxidation States of Tin in Aqueous Solution Citation Browne, Charles Idol (1948) Spectrophotometric and Radiochemical Investigation of the Interaction Between the Oxidation States of Tin in Aqueous Solution. Master's thesis, California Institute of Technology. doi:10.7907/rn6j-5f45. https://resolver.caltech.edu/CaltechTHESIS:05162025-181639771 Abstract The spectrophotometry and radioactive exchange of Sn II and Sn IV in hydrochloric acid have been investigated. It is found that mixtures of Sn II and Sn IV in hydrochloric acid exhibit anomalous absorption of ultra-violet light and that with the extent of this anomalous absorption is proportional to the product of the Sn II and Sn IV concentrations, implying absorption by a dimeric complex of Sn II and Sn IV . It is found that Sn II and Sn IV exchange radioactivity moderately slowly (half-exchange time about 7 min.) in 9N hydrochloric acid. The extent of exchange upon immediate separation after mixing is about 17%, which is either a function of the separation method or an indication that only certain chloride complexes of tin exchange. It is found that Cu I and Cu II exhibit interaction absorption in 6N HCl Item Type: Thesis (Master's thesis) Subject Keywords: (Chemistry) Degree Grantor: California Institute of Technology Division: Chemistry and Chemical Engineering Major Option: Chemistry Thesis Availability: Public (worldwide access) Research Advisor(s): Davidson, Norman R. Thesis Committee: Unknown, Unknown Defense Date: 1 June 1948 Record Number: CaltechTHESIS:05162025-181639771 Persistent URL: https://resolver.caltech.edu/CaltechTHESIS:05162025-181639771 DOI: 10.7907/rn6j-5f45 Default Usage Policy: No commercial reproduction, distribution, display or performance rights in this work are provided. ID Code: 17240 Collection: CaltechTHESIS Deposited By: Benjamin Perez Deposited On: 16 May 2025 19:25 Last Modified: 16 May 2025 19:36 Thesis Files PDF - Final Version See Usage Policy. 23MB Repository Staff Only: item control page

A Spectrophotometric a11d Radiochemical Investigation of the Interaction between the Oxidatlon States of Tin i n Aqueous Solution Thesis by Charles I . Browne In Partial Fulfillment of the Requlrements For the Degree of Master of Science California Institute of Technology Pasadena, California June, 1948 Acknowledge1i en ta The author wishes to express his appreci&tion and gratitude to Dr. Norman R. Davidson, at whose suggestion and under whose guidance the work was performed, and to the United States Air Force, under whose auspices the author worked. Appreciation is expressed to Mr. Rollie J. Myers, for his collaboration in the work on copper. Abstract The spectrophotometry and radioact:i.Ye exchange of snII and snIV in hydrochloric acid have been investigated. It is found that mixtures of sn 1 I and snIV in hydrochloric acid exhibit anomalous absorption of ultra-violet light a.nd that with the extent of this e.nomalous absorption is proportional to the product of the SnII and snIV concentrations, implying absorption by a dimeric complex of 3nII and snIV. It is found that Sn 11 and SnIV exchan ge radioactivity moderately slowly (half-exchange time about 7 min.) in 9N hydrochlor:l.c acid. The extent of exchange upon im- mediate separation after mixing is about 17%, which is either a function of the sepe.ra tion method or an indication that only certain chloride complexes of tin exchange. It is found that cuI and cu11 exhibit interaction absorption in 6N HCl. Table of Contents Part Title r Introduction 1 II Spectrophotometry i III Radiochemistry I '3 IV References V Figures ~· - Page ~o -1- I Introduction Many observers have noted and reported that solids and solutlons containing d:tfferent oxidation states of an element exhibit intensity of color beyond the contribution of the separate states themselves (1,2,3,4). This coloration ls e;enerally believed to be due to the "transfer" of an electron ( ~) between the oxidation states involved, although the phenomenon is by no means completely understood. In the case of so lids, X-1"'a.y analysis has revealed that in some of the cases exhibiting anomalous coloration the different oxidation states are at non-equivalent positions in the lattice. Very little is known about solutions exhibiting this phenomenon. rt is clear that a complete understanding of this interaction color would have far-reaching implications upon the theory of oxidation processes in general, and upon the nature of the electronic energy levels in solutions. Further interest lies in a consideration of the exchange of radioactivity between oxidation states of an element in the light of this interaction phenomenon. If the interaction involves the coming together of the two oxidation states to such proximity that electrons lie in levels common to both states, so that a compound, or -2- complex, is formed, 1 t seems reasonable that such a. system would exhibit radioactive exchange. The present report is a spectrophotometric investigation of the Sn1 I - snIV interaction hydrochloric acid, first in aqueous reported by Whitney (4), with attention to the depend.ency on concentration of the interacting ions and hydrochloric acid, and of the exchange of radioactivity between sn 11 and sn1 v in 9N hydrochloric acid. II Spectrophotometry A. Experimental The spectrophotometer .used was a Beckmann Model DU, wlth 10 mrn light path quartz or Corex cells. On occasion, quartz spacers were ·used to reduce the light path to 1 mm. Measurements were made against blanks of solutions identical with the unknown except th6.. t the blank cont~dned no tin. To protect the spectrophotometer, cells containing hydrochloric acid were sealed with a. mixture of beeswax and ' rosin. Stock Snc1 4 solutions were prepared by dissolving Merck's reagent grade Sn Cl 4 •5H 2 0 in Baker's reagent grade concentrated hydrochloric acid, and diluting to the desired concentration of Sn Cl 4 and HCl. SnC1 4 concentration was determined by reduction with Sb (Braun, powdered)(5)) e.nd -3- subsequent oxidation with stands.re iodine solution. The HCl concen tra t:i.on was determined by titration with sta.nda.rcl Na.OH solution. It was cte:_tennined by introducing weighed amounts of SnC1 4 • 5H 2 0 into standard ECl solutions and titrating with NaOH that under these conditions, Sn(OH) 4 , or at least a non-chloride containing hydrated stannic oxide, was precipitated. The method is not very precise, especially in solutions concentrated in snIV, because of the difficulty in end-point determination, but is found to give results reproducible within 2 per cent. Stock SnC1 2 solutions were prepared by dissolving Baker's reagent grade Snc1 2 .2H 2 0 in concentrated reagent grade hydrochloric acid, boiling with reagent grade powdered Sn, dilution, iotnd s.nalysis. sn11was analysed c.irectly by oxi da. tion with iodine; Sn IV and HCl by the method given above. At no time was it possible to obtain solutions free of snIV by analysis, although the content of th -i s oxidation state was found to be as low as 0.7% of all Sn present. In general, solutions of Sn 11 contained not more than 57& snIV. All handling of Sn 11 solutions was carried out under an atmosphere of carbon dioxide. Spectrophotometric measurements were made in 3 hJdrochlo!'iC acid concentrations: 9.5N, 6N, 3N. In each case, the procedure was first to measure the absorption spectrum of solutions of various concentrations of SnC1 4 , then of solutions of Sncl 2 , U--1en of mixtures of the two, varying the proportion of snIV to Sn11 in the mixtures. -4- The extent of the anomalous co lora. tion was determined by s ubt rac tlng from the optic al d.en s i ty ( D ) of the mixture solution at any wavelength the D of sn 11 and snIV at the same wavelength. In general, snIV solutions were found to follow Beer's Law within the limits of analytical error, so that it was necessary to measure the D of only a few 3nIV concentrations to obtain D at any concentration. sn11 solutions, however, showed marked deviation from Beer's Law, so that many measurements were necessary. The logical extension of the investigation to alkaline solutions of Sn11 and snIV was prevented by the turbidity of these solutions, particularly that of 3nII. As a result, Sb was substituted for Sn and measurements ma.de on SbIII and S.bV and mixtures in 7 .65N KOH. Wi th1.n the time available, it was found that spectrophotometrically clear concentrated solutions could not be obtained. Extraneously to the main purpose of the investigation, measurements were made of the absorption spectra of cu1 and cu11 , a.nd a mixture of these ions, all in 6N HCl, to detennine whether interaction absorption existed in this case. Precision Ana.lytical. Measurements of the concentration of sn 11 were precise to 0.5%, those on snIV to 0.6% and those oh HCl to 2.6%. -5- Spectrophotometric. All measurements were made on steep D- A slopes., so that care was exercised to maintain slit widths at minimurr. values. Nevertheless, calculations of the uncertainty inn, based upon the observed value of the slope of the D- ,l curve and the band width of the spectrophotometer result in 7-20% on the steep portions of the curve, the percentage uncertainty increasing with lower values of D. The observed values of D represent., of course, no~ the Data wavelength A., but rather the ${"T integral between limits ge:.t by the uncertainty in ;t ( dete rrnined. by ;\. and slit width) of a function D:;,. d l . rt is clear that if the change of slope of the D- ;l. curve over the 1.nterval of the uncertainty in J. is so slight that the curve may be taken as a straight line, the contributions to the integral of the intervals~. to ~o and J. to 7-1.. ., wi 11 can ce 1, giving a value in D). precise to the error in reading of the D 'and J. scales on the spectrophotometer. D at var:T.ous each point. This rectilinearity may be checked by measuring ). 's with seYeral slit width settings for When this is done, i t is found that D is independent of slit width above a wavelength characteristlc of the substance under investigation; for Sncl 4 in 9N HCl this wavelength was below 320 mr; for SnC1 2 in 9N HCl below 350 mr. Through an oversight, that of the interaction was not measured, however., by analogy with the SnC1 2 and Snc1 4 curves, 360 mJ'""- may be estimated -6- as a reasonable value. On this basis, spectrophotometric precision is that of reading the instrument and setting the controls, and is certainly less than 1% for any value of D greater than .100. In practice, the independence of Don slit width was not relied upon since slit widths were held as constant as practical with the instrument, giving precision of about 1%. -64 B. Data. Figure I Spectra of Sn1 V, Sn 11 , and mixtures thereof in curve 9 . 5N HCl 16 Figures I .231F SnC1 4 in 9.5N HGl II .309F SnC1 2 in 9.5N III .399F SnCl:d + .381F SnC1 4 in 9 .5N HC'l Figure II HCl snIV Spectrum at Several HCl Concentrations I .231F SnC1 4 in 9N HCl II .203F SnC1 4 in 6N HCl III .225F SnC1 4 in 3N HCl Figure III snIV Absorption at Several Wavelengths I .5F SnC1 4 , )::.310 ID)"' II .3F SnC1 4 , 310 III .7F SnC1 4 , 320 IV .5F SnC1 4 , 320 Figure IV SnC1 4 in 9. 5N HCl I ?--= 315 mA II 320 III 325 Figure V SnC1 4 in 6N HCl I ) = 305 mr-, II 310 mr, III 315 mr IV 3~0 mr, V 325 IDJN - ·1- Figure VI Sn€1 4 in 3N HCl I A-; 300 m14- II 305 mr- III 310 mr, IV 315 m 1 Figure VII SnC1 2 Spectra. at Several HCl Concentrations I .399F SnC1 2 in 9.5N HCl II .382F SnC1 2 in 6N HCl III .372 SnC1 2 in 3N HCl Figure VIII SnCl~ in 9 .5N HCl I °A== 330 mf't-' II 335 III 340 IV 345 V 350 VI 355 VII 360 Figure IX SnC1 2 in 6N HCl I J. :: 330 ,-.,,,....... II 335 III 340 IV 345 V 350 VI 355 VII 360 VIII 365 IX 370 X 375 XI 380 -8- SnC1 2 in 3N HCl Figure X J. ~ I 330 ml"" II 335 III 340 IV 345 V 350 Interaction Absorption in 9.5N HCl Figure XI I :;\ = 360 mr, II 370 mr-, III 380 IV 390 V 400 The values plotted represen t the measured optical density of mixtures of Sn 11 and snIV less the corresponding densities of the ions themselves, as taken from Figures IV and VIII. {snIV) ( C1C2) {3nII) (SnIV) .047F2 .137F .341F .096 .314 .306 .152 .399 .381 .183 .479 .382 (snII) Figure XII I The following mixtures were used: Interaction Absorption in 6N HCl :;l. -= 365 t!l/'1-- II 370 III 375 IV 380 V 385 VI 390 VII iTTT T -9- The follo wing mixtures were used: (snII) (snIV) ( snII) (snIV) .140F 2 .380 .368 .278 .788 .353 .359 . 609 .589 .562 .762 .737 .650 .662 .982 Figure XIII ( C1 C.2) Interaction Absorption in 3N HC1 I :l:l 335 mf"--- II 340 III 345 IV 350 V 355 VI 360 The following mixtures were used: (SnII) Figure XIV (snIV) (snII) (snIV) .042F 2 .186F .225F .084 .372 .225 .104 .186 • 5&2 .130 .469 .281 .149 .495 .300 .167 .372 .450 r Interaction Absorption at Several Wavelengths I C1C2 .15 J.-:, 360 m 1 II C1C2 • J.O 360 III C1C2 .05 360 IV C1C2 .20 380 V C1C2 .10 380 VI C1C2 .05 380 -10- Figure xv Spectra of SbIII a.nd SbII in Alkaline Solution I .022F KSb0 2 in 7.65N KOH II .170F KSb0 3 in 7. 65N KOH Figure XVI Spectra. of cu 1 , cuII, and mixtures thereof in 61! HCl I .05F cucl in 6N HCl II .025F Ct1.C1 2 in 6N HCl III .05F CuCl + .025F CuC12 in 6N HC1 -11- c. Results and Conclusions Figure I shows the absorption spectrum of Sncl 4 , SnC1 2 , and mixtures of the two in 9N HCl and. exhibits the general nature of the effect. snIV under these con- ditions a bsorbs strongly below about 320mf'-, snII below a.bout 350, and the mixture below about 360-370 mf". The absorption spectra of SnC1 4 at various HCl concentrations a.re presented. in Figure II. It is seen that the a.bsorp- tlon in the near ultra-violet increases with increasing HCl concentration. The same data are presented as a family of curves of Das a function of HCl concentration for different wavelengths in Figure III. The linear variation of D with HCl concentration is striking, and extrapolation suggests that snIV loses most of its color in the 300-320 m,,.u range below l-2N HCl. The satisfactory manner in which the snIV solutions conform to Beer's Law is illustrated in Figures IV, V, and vr. A plot of the absorption spectra. of SnC1 2 solutions is exhibited in Figure VII. rt is seen that the absorp- tion ts stronger in 6N HCl than in 9N or 3N. The deviations from Beer's Law of the Sncl 2 solutions are demonstrated in Figures VIII, IX, and x. As mentioned above, no Sncl2 solution could. be obtained free of SnC1 4 : however, deductions from ~~e D of SnC12 solutions of a D due to interaction v,r j_ th the a.mount of SnC1 4 believed to be present did not reduce the curves to even near linearity. No explanation of t h is deviation is available at this time. -J.;::;- The variation of the D of SnC1 2 solutions with HCl concentration may be explained in one of two ways: either the more heavily chloride complexed species ( the concentra. tion of which certainly increases with increasing HCl concentration) are not as strongly absorbing as the lower, or D of all species decreases at high HCl concentrations, due perhaps to decreased activity of the sob.rent, or some associated electrostatic phenomenon. This point is worthy of further study, since the intere-ct:i.on D, and hence presumably the interaction complex concentration, increases steadily with HCl concentration. Whitney a.nd Davidson sho'wed in the cases of sbIII, Sbv interaction that the optical density of interaction absorption is proportionate to the product of the concentrations of SbIII and Sbv. Figures XI, XII, and XIII show that this is true for the snII, sn 1 V case also. This implies that the absorbing specie is some sort of a dimeric complex formed by a reaction of the type: "iZ/'IJ T &.. L,(d lf-a) ~ /'1 iI~LJL {f C-,r-q i/lA :x~d The composition of the complexes involved cannot be de- , tennined from the data. available. It may be noted from Figure XIV that at any one wave length the amount of inter~bsorption increases with increasing HCl concentration. The concentration of action complex :ts presumably very lovr or the D vs. c 1c2 interaction: A curves would show deviation from linearity, since no correction has been made in the concentra.tion of sn 11 or sn1V for the a.mount of ea.ch ion involved in the complex. -13- No interaction abs orption was noted j_n the case of rrlixtures of KSb0 2 and KSb0 3 in 7 .65N KOH; however, the concen tra ti.on of the mixed solutions was so low that the concentration product was only e.bout.001, rather too low to expect observable coloration. exhibited in Figure xv. The spectra. obte.inec are Further work 1s 1ndicated in the field. of alkaline solutions. rt may be seen from Figure XVI the. t strong interaction takes place in solutions of cul and cu11 in 6N HCl. It is interestlng that this interaction causes absorption in the transparent region of the cu1 and cuII ions themselves. Further work is indicated on the concentration and acid dependency of the interaction absorption of this pair of oxidation states. III Radiochemistry A. Experimental A sample of radioactive tin metal was obtained from the U. S. Atomic Energy Commission as ca tcalog i tern number 3c (6) containing the following isotopes: Isotope Half-life Estimated Estimated ~adie.tion (MEV) Quantity(mc) mc/g element Beta Gamma Sbl25 2.7y 1.0 Carrier free 0.8,0.3 present Snll3 100d 1.0 0.16 K,e - 0.085 snl21 62h ? ? 2.6 present Snl23 10d ? ? 0.8 pone Snl25 9m ? ? 2.2 0.74 -14- Since the elapsed time between cessation of irradiation t of the sarnple and its use in experiments was some 120 days, the only isotopes remaining in any significant a.mount at the time of experiment were sn 113 and sb 125 . It is noteworthy that in the decay of Sn 113 , the K-capture leads to the formation of an excited rn 113 nucleus, which reverts to the ground state with the emission of a. 390 KEV gamma ray, with a half-life of 105 minutes. The internal conversion electrons from this radiation, rather than the weak radiation from sn 113 , were used in counting. The Sn srd Sb in the radioe.ctive sample were separated by the method of Pl&to and Hartmann {7), and Al absorption curves run on the separate samples. The results for Sb a.re presented in Figure XVIII, and those for Sn in Figure XVII. The separated Sn was precipitated as the hydroxide with sodium hydroxide and redissolved in HC1 to conxrert it to the chloride. All exchange exper:i.men ts were carried out in 9N HCl with the radioactive tin in the stannic state. With the one exception noted below, the pro ced.ure was to pipette 5 ml of 0.2F SnC1 4 in 9F HCl into each of two previously weighed centrifuge tubes, to one of which was added 5 ml of 9N HCl, and to the other 5 ml of 0.2F SnC1 2 in 9NHC1. After a time interval, to each was added 1 ml of a solution of cscl {28 mg/ml) in 9N HCl, which precipitated cs 2 snc1 6 , leaving the stannous tin in solution. This precipitate was centrifuged, washed with 9N HCJ., dried at 100°c for about 16 hours, and weighed. The drying period permitted -15- the snll3 to come to equilibrium with its daughter rn•:ni 3 • After welghing, the precipitate was meta. thesized with NH 4 0H to the basic stannic chloride, centrifuged, washed, slurried onto glass plates., and counted with a bell-jar type Geiger-MUller tube, using a Higginbotham scalar circuit, The specific activity of the pr~Qipitate was compared with that of the f,nl V...HCl "blank 11 from the sn1 V-sn11 mixture,.-to determine the extent of exchange. Experiments were carried out with intervals of 1, 4, 7., a.nd 30 minutes between mixing and precipitation. To obtain the extent of exchange :tn 8. very short interval after mixing., CsCl was added to freshly prepared Sncl 2 solution. The resulting precipitate of cs 2 sncl 6 was centrifuged off., more CsCl added., 5 ml of the resulting solution added to 5 ml o~ SnC1 4 solution., the precipitate centrifuged, and the above procedure carried out. Precision. It is to be emphasized that the purpose of this investigation was to obtain a semi-quantitative idea of the snII_snIV exchange under these conditions., not to obtain high precision results. By the use of "blank" experiments, it was found that the deviation arising in the precipitation, weighing, slurrying and mounting process was about 2%. • The other major source of error lay in the fact that the SnC1 2 solutions contained up to 5% SnC1 4 , which would decrease the spec1.fic activity of snIV even without exchange. To these may be added the usual counting uncertainty of some 4% for the samples counted to give results precise to some 11%. -16- B. Data Figure XVII 2 Figures, 1 Table Aluminum absorption curve of radiation from Sb separa,ted from sample. Figure XVIII aluminum absorption curve of Sn separated from sample. 47.7 Blank for F 80 73 1.68 2.35 1.83 1.32 67 ~:--~} 92 0.82 1.39 .90 .99 39 51 1.68 1.13 105 69 47 33 9 17 Also, while A, C, D, ancJ their blank were run on that while ea.ch was matche d with its blank , E t 1,.., ey ,,.,_.,_ ua,... 6 not matched t - ot.ner. , • , o es.ch matched glass mounting plates, E, F, and B were run on pairs of matched plates so experiments is F, E, B, (ACD). ww SnClL1 solutions changed between E, F, B and A, B, C chronological order of -r "Blank" refers to the Sn IV -HCl mixture run simultaneously. Background colUlt was fairly constant in t he vicinity of 15 cts/mi:nute 31.1 Blank for E -i~ ( )0.4 47.4 30 F Blank for B 49.6 7 E 50.8 69 47.6 7 D Blank for A, C, D t 43 51.5 4 C 80 47 .6 1 B 21 18.6 0 background) .. Interval be.fore Wt. Counts per Counts per minute Per Cent ExPreclpita.tion Cs2SnCl5 minute per mg cs 2 SnC16 change (m,rr,) { n,~,) (minus ~c A Mixture Table I -18- c. Results and Conclusions: It may be seen from Figure XVIII that breaks occur in the aluminum absorption curve of Sb ra.dia tion at thicknesses of 107 and 207 mg/:;2 , correspondj_ng (8) to electron energies of 0.36 and 0.6 MEV, respectively, as compared with reported (9) values of 0.3 and 0.6-0.7 MEV. Also, on Figure XVII, for Sn radiation, on Curve A there may be seen a definite break at a thickness of 125 mg/5a2 , and a rather doubtful break at 11 mg/~ 2 , corresponding (3) to .40 and .087 MEV respectively. The reported (10) values of tbe gamma ray energies in the decay of Irt -::-113 and Snll3 are 0.390 and .085 MEV, respectively. Since the conversion electrons should have energies of o.363 and .054 MEV, respectively, it is not clear why the observed values should correspond so closely to those reported for the energy of the ga.mma rays. Consideration of Curve B, Figure 16, reveals good linearity of the three points corresponding to thicknesses of Al of 45, 62, and 118 mg/~ 2 . If Sb 125 had been present, points corresponding to thicknesses above 107 mg/§R2 should be displaced to the right of the line def'ined by the fi:rst two points ( see Figure XVII). Calculations based on the uncertainty in this point and the corresponding point in the curve f'or Sb indi ca. te that the Sn 113 con ta.:ined Sb 125 to not more than 2% by e.ctivi ty at absorber th:tcknesses of about 8 mg, which was that present in exchange experiments. -J.'d- It is concluded from these experiments that snII e..nd snIV exchange radioactivity in 9N HCl at a fairly rapid rate, with a "half-exchange" time of a.bout seven minutes. Of particular interest is the 17% exchange found on immediate precipitation, for which there are three possible explanations: first, experimental error; second, that this figure is associated with tbe precipitation method of separation, and third, that there exists in the tin solutions chloride complexes which exchange immediately, but are present as 17% of the total tin in solution, in slow equilibrium with the other species present. This latter explanation is worthy of further investigation, as could be done by noting whether the absorption spectrum of tin solutions in HCl changes slowly upon dilution with water. Further work, also, is needed with solutions of snIV and snII at lower HCl concentrationo References 1. Hofflnan and Hoschile, ~ ' ~, 20 (1915). 2. Biltz, z., anorg. ~• allgem. ~ - , 127, 169 (1923) 3. Wells, Am. Chem. Jour., 26, 268, ( 1901). 4. Whitney and Davidson, J. A m . ~ • ~ • , ~ , 2076 (1947) 5. Kanning, Quantitative Analysis, 232 (1938). 6. Radioisotopes, Catalog and Price List #2, September 1947, u. s. Atomic Energy Commission, Oak Ridge, Tennessee. 7. Treadwell and Hall, Analytical Chemistrz, p. 235, Vol. II, 7th Ed. 80 Fowler, W. A., Nuclear Phys~ Notes, Calif. Inst. Tech. 9. Nuclti Formed in Fission, J. Am. Chem. Soc.~, 10. -- - 2411 (1946). - Seaborg, G. T., ~ - Modern Phys. , ~, 1 {1944). ·tsa · n , Snf'l, and Mixtures thereof 1n 9.5 N HCl S pee t ra O D .-·•. r' .. ·- • · l. :-:,::~ : :-:-}~ ..::,~= ->..:~:- ~~ :; : i. W&velength ( millimiorons) Figure I Sn&~peotrum at Several HCl Concentr&tiona D ,. ' : 1:· :._ . . :.._....;.:..: :.:. ... ,.. , . . ~:~:F" -i - .. :<~--;-.:~ . _. . ;·:~~~I: . -,---+---r· ·- ·· ··.: :.1·.· ······ ·· i -, . -~.-..--. -- ::;~ ;!:~: : .. •·· - ! .. ••• • -, -- . ..:. t::;. j ,, .• , •. 1, ..... ., .......... · -J: .. . . • j •· : :.:j ' • ·r • · .. . . • .. ·., .. • • •..- · : .-, JI . • • • . . . ; •• 350 Wavelength (m1111m1crone) Figure 11 t I • . ,____ ··- · t1·. :: ,.. :•··••>l -- .: :" :.f:.•: • - t L· Sn ~Absorption at Several Wavelengths Norma1 RCl Concentration figure III 1. D o. -· -- . .· :·: -·: •·•. • l • • I ·- ·r ----..--t-- : j ; •5 Formal Concentration of Sn Figure IV ·•- - ·+------ii---+-- + - ~ - + - . ; . . . . - t - - . - - t - - - - + - - - - l Snji in 6N HCl . , . . . ·•· - - ... , : ... : : : '.:: ;· ~i :. :- ~: '. ; : ' I • ' :p : D Forma.2• Boncentre.t ion of Sn Figure V 1v Sn,.... in 3 N HOl D o . , -.........---.--c:i' . . -i---1-_;__-'---l___. -~.?;.~ , ; .j' .. I ! ,I .c l J r· .j -i ' fl o. 5 H 'O Formal Conce nt ration of Sn Figure VI I ' Sn II . Spe ct r,;i. at Several HOl Concentrations ., ' •· ·•--,.---· ., ' ; -•- -•-t - - :t D ~..:. :-f---~:_ ;~ :-r-:-:-~: ·1.. : ·: 1 Wavelength (millimicrons) Fi g 1 :re VII •·• . . . i ~-i~ ~ ·t . L~ •· :<:i : -· 4 • ,,... .. ·-·· -· •· · ·1· ···- -r ---.. FormAl Concentration of Sn Figt!re VIII Snil in far HCl D I ·I -·1 Forrnril ConcentrP.t 1,-011 of Sti figure IX Sn II' in JN RCl Formal ConcentrRtion of Sn Fig-•ll'e X Interaction Ab ebr ption in 9., N HCl }\ ::J: D . : ·· · . ; : : : : . ; : ·.: - • , , ~_ :· :. ;· ·: : ~: ' : JI Sn tit :::-::L~ . . :. •:: ;. : -r1:: !:'.: : .:-::. : : > - Sn Formal Concentration Product Figure XI : · - t-- . .• .- ·• ·· t·· · Interaction Abs orption in 6 N HCl D • 0. 25 SnJr - Sn"' F -Jr:::O!l c ,.mc entre.tion .PJ::oduct F·i gure XII L i Interaction l'.:bsorptl.on in 3 N HCl D .1 i 0.1 0.2 If Sn -srP'- }'or ,cPi l Com;:entretion Product Figure XIII Interacti on 1\"b s or ption a.t Several WAvelengths ..! .. . -t- ·-· · •1. t · D Normf!,l Conc entr s tion of HCl i'igure XIV SpectrR of SbJI and Sbfi in Albline Solution .. j., . .. : · ·:--! r··:•·:- ~7:· : r-: .. . ~ · ·- · : - 4 . '"-:. - .. i· ~-::--r-.: __. :!:. ~ ·.:.·1:·· :j : :· I: . • •: !\ • ; :~ -:-·:.• :.: .. .. ••·I · · ' ~-:-:1:---- -- .fl I . !::;: D .. i .. -- .. .. • -~-l • ·. .-.-. . . ' · · 1· ' ' ! :_~:~ .. ·__ _:!..___. _. __ _: .. • - • -l - ;. ~: :.: : . ! . . . . . .. ; + c· . - ' • \-- · :Figure . xv ·• · .>i • __• -- -'--- .i...: Wavelen~th (millimicrons) , • • ' •• ., •__ , ' _. _ _ • : j • , • • · ·. Spectra of Cu I , Gu II , and l,l'i.x)uree there of in 6N HCl · ·.j· :.:~..:E:.i D •-:.:r ----.; ... .,. ···1f,,: ~:; ... . : 10~0 ~Avel Hngth (millimicrons) Jigure XVI Al Absorption Curve of RA-diation from Sn Separated from Semple 300 Al 'l'h i ckne s s (mg/cm~) 1.00 II · 1 .. .. i ,:_ ... ... ,.00-..,....+\'--'-l--~ ;:.·i :·.. •· ·:··, -+'-+-+-,-+ -~.;.....+-+-+-+--'-+,'- :j~ · ..+--.-+I_:T+ ITf~< *.·J~ F~ l r4. f......+~+-+-++-=~~~+~ \:t;:\'.\t T\{;!; fl}f\; '.l l?ii:i: [: : : ::r ~ L _:·. . .:·: !: : .. • :·:=rr1.~=-~·: -. . ~: . . : :.:;; : : . . • +, : :.:.: : 3. o t-·-···.,. ··•· - - t -.....-t---+--+---,---~--t--......,.--t----~~_,___,_...,..._---,_-+-_··....:}_i.., :t-1'.•__ fl_.:....:1.,.i,...:.__: 1-:--~'-f~ .,.....-+-........--+---+--+~ u: , ... C ~:\ 0 0 - ·1 Al Thickne ss (mg/ cm2) Fir:ure XYI I I Al Absprption Curve of Ra.dita.:tion from· Sb Al Thickness ( '!Dl!,/cm2 ) Figure XVII I