ROBERT0.SAUEK AND
1794
tween the coimposition of Solid Solution A and Na2C03. TABLE I11 THESYSTEM Sa~CO3-Na2SO~-SaOK-H20 AT 100 '
soln. 1 2 3 4
5 6* 7 8
R 10 11
12 13 14 1
2 3
4' 5 6 7
8 9 10
Solution Wet residue composition, composition, weight per cent. weight per cent. Naz- Nal- Na- Naz- Naz- Na; COS SO4 O H COS , 5 0 4 OH Univariant Line A 28.5 28.0 26.4 25.4 23.3 23.8 21.5 17.9 17.4 14.0
10.8 8.0 5.0 3.2
3.2
0 0.9 2.9 2.5 2.8 2.6 2.6 4.2 2 5 3.8 2.3 5.4 1.9 8.6 2 . 0 8.7 1 . 7 12.0 1 . 2 15.4 0 . 8 18.9 0.6 23.2 0 . 5 26.9
3.1
49.8 53.5 54.6 61.6
37 3 24.; 22.0 23.8
. . . . 62.6 56.9
67.1 61.5 68.7
18.4 l(i.8 13.6 13.3 12.6
. . . . 55 2 50.9 51.9
8.3
7.1 6.8
Solid phase identification
??arCOa.HzO, S.S NacC0rH10, S.S. 2 . 5 NaKOs.Hz0, S S . 0 NarCOvHzO, S S . . . NarCOa.Ht0, O.!) NazCOs.H?O, 2 3 N~zCOVHIO. I1 (i NazCOa.Hz0. 1 .(iN ~ z C O V H I O , 0 NarC01.Ht0, S.S. . . NazCOrHnO, S.S 0 . 2 NazCOrHzO, S.S. Y . 2 NazCOa.Hz0, S S 1 1 . 0 NazCOrHtO, S.S. 0 1.0
Univariant Line B 4.0 26.0 0 19.3 70.5 0 3 . 4 24.5 1.5 18.3 71.8 1.8 3.0 2 1 . 5 3.4 . . . . . . . . . 2 . 9 21.3 3 . 3 15.2 84.8 0 2 . 4 19.6 5 . 1 15.3 7 8 . 8 0 2 . 2 17.:3 7 . 0 12.9 79.7 0.4 2 . 5 11.'7 1 1 . 8 . . . . . . 2.1 7 . 5 16.3 1 2 . 0 73.5 0.2 2.3 4.'7 2 1 . 4 1 2 . 9 7 1 . 9 2.6 1.3 2 . 0 30.4 11.0 6 5 . 6 8.0
Na&O4,S.S. NazSO4,S.S.
. . . . . . Nazs04, S.S. NanSO4, S.S. NarSO4 NazSO4,S.S. NarSO6,S.S. NarSO4,S.S. NaiSO4, S.S.
L)AKLVIN J.
\'ol.
A~SAD
&?l
attempts was made to study completely the cornposition of the solid phase in the art1a C J .~Y ~ & I : ~ . Ka2COa which covers the major portion o I tllc diagram, since i t was felt that .tn :idequate estimate of this compositioii could l ~ c .:!::*(le by utilizing the data illustrated in Fig.:3. Acknowledgment.-The authors 1vi.h :o express their appreciation to -1lbert I(Lauii'iii:iii and Howard Jaffee of the Pctrogrnpliic D q x : : ~ ~ i i e n t a t this station for doing the 1iiicrc;my);c v;-ork, and t o Richard A . Brow:, Che1 in charge cif tlir Alkdiiie Xluiiiii John E. Coiiley, Chiel of the Chei iiig Ullit, for \-alua'nle' suggestions :ii:cI i iri iicisiils during the in\-estig-LLion.
Summary
1. The iiiajor portion of the 4-co1 teiii NazCO3-_'ja~SO4-NaOH-H?O L been determined, involving the deternii!Ia!ioii oi parts of the three related 3-cornponei1t systems, namely : (1) Na2C03-NaOH--H20 ( 2 SLt?SOaNaOH-HZ0 and ( 3 ) SazCOn-Sri.S0*--IT~C)at L i i c same temperature. Ordinary chcinicT:-l inethods were used in solution and sold phase‘ ar:ai:.-sc:s a:id the petrographic microscope 17 as L > I I I I.! , y ~ tl) l identify the solid phases. 2 . In this system for the co*iceiitraii:iii raiipc'
Solution 5 given G8 a NaOH calculated by difference. hours agitation time, all others 20 hours. Solution 3 given 68 hours agitation time, all others 20 hours.
Similarly along line "B" the extrapolated tie lines intersected the Na2S04-Na2C03 axis a t points between Ka2S04and Solid Solution B. No
[ (1ONTRIBUTION FROM THE RESEARCH LABORATORY G F THE GENERAL ELECTRIC COMPANY ]
Dipole Moments of Linear and Cyclic Polymethy~polysiloxanes BY ROBERT 0.SAUER AND DARWIN J. ME.^ I n connection with an extended study in this Laboratory of the physical properties' of polysiloxanes we have had occasion to investigate the dielectric beha.vior of the pure liquid polymethylpolysiloxanes reported recently by Patnode and Wilcock.2 We sought to gain an insight into the structure of the polysiloxanes, and we hoped, in particular, to obtain a t least an approximate value for the silicon-oxygen--silicon bond angle from the dipole moments computed by means of Onsager's equation.3 Upon evaluation of the accepted physi(1) The properties so far discussed include: (a) crystal habit and configuration [Burkhard, Decker and Harker, THISJOURNAL, 67, 2174 (1945)]; (b) molar volume and viscosity [Hurd, ibid., 68, 361 (1946) 1; (c) vapor pressure and visca@ityrelations [Wilcvck, ibid. 68, 691 (1946)l; (d) molar and group r&
