Volume Changes for Metal Solutions in Liquid Ammonia R Y PHILIPMARSH ALL^ A N D HERSCHEL Hu\ RECEIVED MARCH 30, 1955
TABLE I VOLUME
CHANGES FOR
LITHIUM
SO1,ITTIONS
IN
LIQUID
AMMONIAa
I
In the cmrse of recent research i t was necessary to obtain the volume change associated with the solution of lithium, sodium and potassium in liquid ammonia. That the solution of these metals in liquid ammonia is accompanied by a relatively large increase in volume has long been known. From the densities of sodium and potassium solutions it has been shown that these volume changes pass through a niaxiinuin at ahout 3 However, the more recent publicati~ii of the densities of lithium solutions3 did not include values for the accompanvinq volunie changes. The mole fractions of lithium and the densities of these solutions as given in the above article are shown in Table I along with the volunie changes calculated from these data. Since inany properties of these solutions have been shown to be the same or a t least quite similar it seems significant to note that the lithium solutions, at least according to the available data, do not exhibit a tnaxiinuin. As is shown in Fiq. 1 the volume change incrcnscs steadily :is the solutions become more dilute.
0.0331 ,0571 0713 ,1180
0.639 ,611
-1fi.7 40 1
,597
1 LS
.5 . 3
-12,.i
0.1557 .IOlii ,195s . 21 0.i
0..53 .5lS ,498 ,
Lithium densities determined a t -33.2" hfcyer and Martens.3
.490
41.4 41.4 38.8 :>7. 9
by Johnson,
are extremely sensitive to errors in the density determinations. Errors of 0.1% in the densities would be sufficient to give a somewhat flat maximum to the curve and errors of the order of 0.5% could give a curve quite similar to those obtained previously for sodium and potassium. However, a t the present time the conclusion that these metal-ammonia solutions are the same or even quite similar in this respect does not seem t o be a fair statement. It would seem that further and more precise data, especiallv in the dilute solutions, is desirable. DEPARTMEST O F CHSMIS I R Y
PURDGE VSIVERSITY TSDIANA
12AFAYE1.TT.:,
The Thermal Decomposition of Tri-n-butylborane 45
BY LOIJISR O S R N B ~ ~ U M JGSE 6,I RECEIVED
40 0
E
*
. .35 a M
U 30
25
1
2
3
4
5
6
7
=if. Fig. 1.-Volume changes accompanying the solution of the alkali metals in liquid ammonia, the increaqc in volrimc, AV/g. atom, as a function of the normality, N.
It should be noted, as pointed out by Johnson, et al., that the volume changes in the dilute range (1) Department of Chemistry, h l h i o n College, Albion, Rqichigan. ( 2 ) C. A . Kr:iii';, E. S. CarnPy a n t i \V. C. Johnson, T r t r s J O U R N A I . , \V,C . Jhns,ma n < l 4 . \V M e y m , i W . , 5 4 , 3r;?l (1932). (3) W.C . Tohnson A . \V. Afe-yFr rind I t . n Rfsrtrnn i h z d . . 72, lP,t!?
4 9 , 2206 (1
