Document bO7GBKRdaDKOG68ed54ye7oq0

f ni~ / THE HYDROUS OXIDES t l BY HARRY BOYER WEISER Professor of Chemistry at the Rice Institute First Edition MeGRAW-HILL BOOK COMPANY, Ixc. NEW YORK: 370 SEVENTH AVENUE LONDOX; 6 i S BOL'VERIE ST., E. C. 4 1926 PLAINTIFF'S EXHIBIT UC-1530 ! i 5 cs C "5 CC * CO cs S: S c; S 85 S -S 5 - 2 o` *5 c r^"g'^ Uf^I it2!lh I?i! ill 5 " I s = 5 2 r- > - C = * rl .............................s 5 J >> _L Z g cUrn .2 z ^ _ 3 3 ^ 2 M u 3 = 5 >, II Ou. & C3 z > "2 --= 2 111 i.2 0 a -- 7. rz ' " '7 S 7. o c .- c > i= s^9 r m 2 -J = * pci S - = t C Z) ~ 5n$, c - 1- a = .2 = . tc-; '52. ir; * *= i-l |3 ~ ' J1 = 5 ! gc. 11.2 _r - s y 2 53 -- iri hog-s- 3=E >.?5 n_ . J-- V. 2 2 5i? J: = b " * E I_ * II6 'z -s j ; g-3 "3 - i M- 1H J ,, 2E g -- - t: M a-_ 7^ - .=" Ir. = 7r -- r .a r a ~ a s.3 = 3 -a 2 ~ ?r= 7. d ' z .z 7' .2 r r-T J i -= = S i J = '! 3 i i 1 =.z. | r z- rz s- 7 = " r= r. " =z =-- =y -5/* = = 7- -= ^ E i? S . 2 2 = * 5T - - -- -2 V. -a E H z -- -j r: =i tc z = r: I 1 -.-- ** Jj 2 jl.s T- != N{ 2 : s' ~ "5 Js -" . s 7. --i^: = =2 ^ ss =_ -- *U I I 2^ _ |S^ I I 3a" Ep s> r5 >* ^ -- j S > a iZ 5 Z " >= .s 1 f .1 = =?mm: =< 5 ~ -- 7. S a S S a ^ g -f "3 < .S_ -s Ia =* = =? = ? 1<s I*f. o c-_ --- --r = ^ X- = -f -- s > 2 -O _ z z b 1|| I I> = .J -- Ms* 2 53 a vr. a r. S ~-- cr~ " 7 z . ,_ Z r _2 ----: Xa --* 3 -2 s. 145 - s * J -3 ^SH .= 2 f ? / =i ^ =: 2 _ ; v= z 5 ^ r z -- - z, 7 . S ~ " s ?. 7 b -- a Fi S a 1 ?: < T* cs sH pS|5 Eo -2 Iw 5,, zj-, t'is s^2 5- r. " 2 `-^5 ri - 5= g* -5 - ^ S - V" 3rfS>; ?s ,r 1 =3 ; 1.1*1 "sJH i. ;5 v; 'M ri i 111 2 - ^z ; 5" ^jj==-- r = ?- 2 7. P| Zi s ^ i i.iiSj /: n 7m r **7- BERYLLIUM. MfOSESlUM. ZIXC, r/ADMIUM, MERCURY 167 ia minute intc-rlnoi/g crystals1 of wMt has been assuiycd to be CS ,. iv r- basic chloride. /People are unable/to agree on the for/hula of the hypothetical s/lt, and it is probably only an indefinite solid r.` solution of magnesium oxide an/chloride. The emoride may be be dissolved oui/ completely with/boiling water, lea/ing hard mag r: nesium oxidS. The cement c/n be prepared by adding water to a is suitable mixture of dry components.1 It /ossesses marked de mechaniea/ strength and ij used for cementing glass and metfcul of and for making artificial /tones; c.g., xylolitn is made from saw ml dust, cement, and water/ // it The yondenev of ea/ined magnesia jo take up water and be cxpand.ls of importance in the cement industry, since the presence ice of as 11/ucii as 2 to 3 nor cent of uneoinj/med magnesia w/uld give ar a concrete that would disintegrate/from excessive expansion.3 il) iDyfiddition to tlm applications mentioned, hydrous^/nagnesium hyd/oxide has be/n substituted io/ charcoal as a clarifier in the 'ol - refi/Jng of suga/4 Its mild basic action lias ben utilized in "he plylrmaccutiea/prcpnrations as/in antacid. Mtfk of magnesia lo is/a fairly stalne suspension of /he hydrous oxide that is widely se, o/nployed as / mouth wash: in the pre pa ratio/of modified milk ilie /or infants and in combayng- hyperacidity of the stomach. 'pi- Ithythmic Bands.--The precipitation of magnesium hydroxide ::r- in gelatin in the form of rhythmic bands has been investigated quantitatively by Popp.3 When ammonia diffuses into gelatin in containing magnesium chloride, it is found that with increasing :ily concentration of magnesium salt, the rings increase in number ;ed and thickness, and the space between them decreases; with dimin ' iii-- ishing ammonia concentration, the rings decrease in number and .eel thickness, and the space between them increases; adding ammo ~te nium cliioride causes the number and thickness of the rings to rig. decrease and the space between them to increase; with diminishing i;h gelatin concentration, both the rings and the space between them to increase, the number remaining the same. The rhythmic precip- i of J, ,nn : ' Lvhmaxm: Chan. Zlg., 26, 345 (1001); Krieger: Ibid., 34, 240 (1910). ! O'. Kramer: German Patent 143933 (1902); Lyte and Tatters: Brit ish Patent 11545 (1S90). 3 Camphell and White: J. .-lm. Chan. Soc., 23, 1273 (1906); Campbell: J. Ind. Eng. Chan., 1, 065 (19091. 4 Hake: J. Soc. Chan. Ind.. 2, 149 (1SS3). 5 Kolloid-Z., 33, 20S (1925). 1GS THE HYDROUS OXIDES itation takes place also in clay, agar, silica gel, fine sand, and glass beads in water. To account for these and other Licscgang phenomena, Wolfgang Ostwald1 *postulates the existence of three principal diffusion waves in all reacting systems giving typical periodic precipitates: The added electrolyte diffuses into the gel; the electrolyte in the gel diffuses outward; and the electrolyte produced by the reaction may diffuse in both directions. In many instances the soluble reaction product possesses a higher rate of diffusion than one or both of the reactants. Ostwald assumes further that many and probably all reactions giving Licscgang rings arc balanced reactions. Precipitation, therefore, depends on certain critical concentrations of reactants which vary over wide ranges through the interference of diffusion waves. In support of the theory, it was shown that many Licscgang rings are destroyed by subsequent introduction, by diffusion, of the electrolyte produced in the reaction. Thus, bands of mag nesium hydroxide are destroyed by allowing ammonium chloride to diffuse into the gel supporting them. The converse of rhyth mic precipitation, namely rhythmic solution, mat' sometimes be produced by adding a reaction product. Thus a uniform precipitate of lead sulfate in gelatin gel containing ammonia is converted into rings by the interdiffusion of concentrated ammonium chloride. Continuous prccipitatiou results if one reactant is replaced by a compound not giving a balanced reaction, as evidenced by the failure to get bands when alkali is substituted for ammonia in the precipitation of magnesium hydroxide in gelatin. The distribution of chloride ions in a gelatin jelly containing magnesium chloride was found after the diffusion of ammonia, to show periodic variation between values much higher and much lower than those in the original gel. Wolfgang Ostwald's theory of rhythmic banding is merely an extension of Holmes'5 diffusion theory based on Frick's law of diffusion. The influence.of such phenomena as sunersatumtion,3 peptization ana coagulation of the precipitate,4 adsorption 1 Kolloid-Z. (Zsigmondy Festschrift). 36, 3S0 (1925). J. Am. Chem. See., 40, 11S7 (191$). > Ostwald: "Lchrbuch all.icm. Chcmic," 2d cd., 2, 77S. 4 FiiErxDLicii: "Kajiillarchcmic." 2d ed,, 1009 (1922); Sex and Dhar: Kolloid-Z., 34, 270 (1924). ; 1 . i j j ; j ' I j ! nun: of rear second: Stab been p typical methyl The amoun zinc o exact : sample less tl newly fioccul gmdu: oxide than f: As in mass f than t hydro' of wa; where ISO0, at a !r. by Dc 1 Hr 5 Ni; 4 tic 4 Li> ` Fit 136, -h 4 Di (192:5). : C,,, Lit i. and -untig three typical the gel; t-.rolytc n=. In ; higher )?t wald - giving icrefore, ~ which n waves. osegang tr.ion, of <>f magchloride iliytiimrtimos uniform i.nnonia tinted - if one .danced _*i alr.nl i . nesium in a .-d after between :.;inrd gel. .s merely .-k's law : rse.lurndsorption r.nd Duar: BERYLLIUM, MACXESIUM, ZIXC, CADMIUM, MERCURY 169 of reacting solutes by the precipitate.1 etc. is looked upon as a cCi"nnr;.j i~y factor in the banding process. *~7?rabic-'~id; of b--d- I'^cneslum hydroxide in water have not been prepared without the aid of a rrivvytv^L-ldd-iiIlLl but a typical sol of great stability is formed by shaking magnesia with methyl alcohol.2 IItdrous Zinc Oxide The voluminous precipitate obtained by adding the calculated amount of ammonia or alkali to a solution of zinc salt is hydrous zinc oxide, the.amount of adsorbed water depending on the exact method of formation, the temperature, and the age of the sample.3 If the precipitation is carried out at 100, it contains less than 1 per cent of adsorbed water. Although the oxide newly formed in the cold is a transparent, gel.4 it quickly becomes flocculcnt and later powdery, the change being accompanied by a gradual transformation into the crystalline state.3 The hydrous oxide ages more rapidly if precipitated from chloride rather than from nitrate: r.nd in the presence of alkali rather than water. As in the case of hydrous beryliium oxide, the microcrystallinc mass formed on standing in the cold always contains more water than corresponds to ZnOTI;0, and in ihi= state, it is probably hydrous zinc hydroxide. Kaufmann* observed a gradual loss of water on heating a precipitated hydrous zinc oxide to 125, where it had the composition Zni'OH'i; which it maintained to ISO0, and then broke down gradually, giving anhydrous ZnO at a low red heat. There are no hydrates of Zn(OII);, as assumed by Do Forcrand7 8and Boedecker*.5 1 Rradcord: Biochan. J., 10, ICO (10051. : Xeoberg and Klv.ai.d: Kolluid-Z., 2, 354 (100S). 5 Goudriaax: Rcc. tear, chim., 39, 505 (1020). 4 Linder and I'icton: J. Chan. X.ic.. 61, 130 (1S92). 5 Fricke and Ahrxdts: Z. anorg. Chan., 134, 344 0024); Fricke: IbiiL, 135, 4S (1024); Bonn and Xiclassex: Ibid., 132, 1 (1024). Dissertation, Miinchcn, 00 (1013); cf. Pascal: Compl. rend., 177, 705 (1023). : Compl. rend., 136, 30 0002). 8 Liebig's Aim. Chan., 94, 35S (1S55).