June, 1942
1469
ACTIVITYCOEFFICIENTS OF BIVALENT METALNITRATES TABLE XI1
TABLE XI Lowest acid concn. ( N ) necesary for reaction HzS04 HCI
Reducing agent
AszOa HzC201 HzCO C~HBOH
0.0 0.0 7.8 2.0
Order of reaction concerning reducing V" agent
2 1 2 1
0.0 0.0 4.6 2.0
Temp. coeff. in HzS0, solutions
1. 0 3.2 1.6 2.8
1 2
1-0 1
for the oxidation of oxalic acid. The catalytic effect of phosphoric acid seems to be connected with the arsenious oxide and not with the vanadium. Nitric acid is a peculiar and very sensi-
[CONTRIBUTION FROM
THE
t i / , in minutes Accelerator ReducUpper and With, lower final Without accel. in agent Formula concn. ( N ) accel. max. concn. As203 H3P01 0.0225-0.3 ' 182 23 , 2 5 -1.0 HzC~01 M n + + 86.25 18.25 HZCIOI F e + + + . 0 5 -0.5 86.25 440 H?CO "01 .0026-0.02 186 46" ,028 - 0 . 2 5 485 CzHsOH HNOs 32"
pactor of acceleration 7.9 4.7 0.2
4.0 15.1
a The end of the induction period; from this point on the reaction passes very quickly.
tive inductor in presence of formaldehyde and ethyl alcohol. JERUSALEM,
PALESTINE RECEIVED JANUARY 26, 1942
CHEMISTRY DEPARTMENT, AUCKLAND UNIVERSITY COLLEGE]
The Activity Coefficients of Some Bivalent Metal Nitrates in Aqueous Solution at 25' from Isopiestic Vapor Pressure Measurements BY R. A. ROBINSON, JEAN M. WILSONAND H.
In a recent communication' isopiestic measurements have been recorded from which the activity coefficient of calcium nitrate a t 25" has been computed and found to be considerably lower than the activity coefficient of calcium chloride.? It is a matter of some interest, therefore, t o obtain measurements on other nitrates of the alkaline earth metals and similar bivalent metals. We are now able to report results on magnesium, strontium, barium, cobalt, copper, cadmium and uranyl nitrate.
Barium Nitrate Ba(N0s)z
0.1865 ,1899 ,2006 ,2265 ,2490 ,4317 ,5344 ,6440
0.5498 ,5659 ,6681 ,8318 1.043 1.294 1.474 1.583 Strontium
Sr(N0a)z
KC1
Sr(NOd2
0.08822 0.1184 0.4522 ,7331 ,09650 .1290 ,7574 ,09980 ,1330 ,1205 ,1591 ,9450 ,1443 ,1898 1.264 ,2069 ,2723 1.363 ,4088 1.565 ,3125 ,4496 ,5820 1.795
0.8746 ,9118 1.099 1.419 1.871 2.442 2.885 3.145
1.585 1.631 1.662 1.757 2.040 2.065 2.120 2.197
3.144 3.262 3.362 3.600 4.371 4.439 4.609 4.831
Nitrate KCI
Sr(N0a)z
KCI
0.5870 ,9330 ,9666 1.199 1.582 1.700 1.952 2.210
1.872 1.921 2.206 2.446 2.811 2.974 3.498 3.909
2.319 2.3% 2.712 3.014 3.456 3.658 4.314 4.843
(1) R . A. Robinson, THIS JOURNAL, 62, 3130 (1940). (2) R . A. Robinson, Tvans. Favadoy S O C .36, , 735 (1940)
KC1
B a ( N 0 3 ) ~ KC1
Ba(NOa)?
KCl
0.09144 0.1151 0.1450 0.1775 0.3316 0.3743 .1155 ,2184 .2591 ,3598 ,09208 ,4030 ,1194 ,4358 ,1489 ,2240 .2664 ,3961 , 1413 ,1735 ,2899 ,3322 ,4022 ,4434 Cobalt Nitrate KC1
Co(N01)r
KC1
CO(NOd?
KCl
0.1419 ,3293 .4263 .5498 .go28 ,9322 1.445 1.490 1.948
1.137 1.155 1.214 1.223 1.362 1.421 1.477 1.487 1.650
2.009 2.038 2.177 2.203 2.499 2.640 2.767 2.810 3.178
1.760 1.815 1.886 1.935 1.990 2.198 2.244 2.261
3.454 3.587 3.772 3.898 4.033 4.578 4.678 4,738
Cu(N0a)r
KCI
Cu(N0a)z
KCI
Cu(N0s)r
KCl
0.1091 1211 ,1921 ,2333 ,2382 .2585 .30GO
0.1514 ,1820 ,2691 ,3300 ,3383 ,3684 ,1411
0.4241 .5389 ,7310 1.000 1.183 1.390 1.529
0.6132 ,8181 1.150 1.668 2.032 2.442 2.766
1.618 1.701 1.915 2.158 2.283 2.415
2.936 3.136 3.633 4.178 4.501 4.828
Cd(N0a)z
KCl
Cd(N0a)p
KCI
Cd(NOp)i
KCI
0.1134 ,1217 ,1559 ,1975 ,3309 ,4141 ,5345 ,6409
0.1571 .1707 .2190 ,2778 ,4766 ,5061 ,8012 ,9786
0.6730 0.6863 1.041 1.138 1.206 1.267 1.531 1.681
1.031 1.048 1.672 1.848 1.974 2.082 2.597 2.888
1.841 1.873 1.989 2.162 2.315 2.381 2.638
3.201 3.255 3.497 3.824 4.150 4.269 4 810
c O ( NO3)2
0.1022 ,2297 ,2932 ,3715 TABLE I ,5798 CONCENTRATIONS OF ISOPIESTIC SOLUTIONS OF POTASSIUM 5962 CHLORIDE AND BIVALENT METALNITRATESAT 25" ,8645 Magnesium Nitrate ,8881 Molality Molality Molality 1,109 Mg(N0a)g KC1 Mg(NO1)z KCI Mg(NO3)z KC1 0.1322 .1347 ,1430 ,1605 ,1739 .2931 .3517 ,4197
s. AYLING
Capper Nitrate
Cadmium Nitrate
(Concluded)
~ A B L FI
brought into equilibrium with solutions of potassium chloride by the method previously described, the concentrations of the isopiestic solutions being
1 ranyl Nitratr 1\/IOldllty 1 ' 0 ? ~ N 0 ~ ) 2 KCI
CJ
hlolality KCI
hIolality
T i 0 (NOa)
KCI
1 O.(NOdq
o 7557 I ,378 1681 0 8650 1 026 3833 1 020 1 999
09:10 7156 2492
2865 2982 4797 3,j1(,
4441
4627 7920
y3;0
1173
titid?
251
1 219
2 525
1 332
3 ,599
' 654 697
li 715
xx;
1.381
I'W3;i
4801
1 1 759
jc,
$16.3
1457
*
recorded in Table 'Table I1 contains values of the osmotic and actixqty coefficients calc11lated from the experimental results in Table I. The selection of referenct. values €or the activity coefficients a t 0.1 -11 was a matter of some difficulty; provisional value.; were obtained by plotting the osmotic
1 498 3 248 I
