N otizen
o
o
o
Lo
u
O
un
o
1.173
0.9385
0.7508
0.6006
0.4805
0.2803
0.1730
0.2 M a q u eo u s N aC l solution
1.353
1.374
1.393
1.280
1.299
1.309
1.224
1.242
1.251
1.177
1.191
1.201
1.141
1.155
1.161
1.085
1.091
1.097
1.053
1.056
1.060
1.403
1.318
1.259
1.205
1.164
1.101
1.065
1.173
0.9385
0.7508
0.6006
0.4805
0.2803
0.1730
0.3 M a q u eo u s N aC l solution
1.371
1.377
1.355
1.274
1.305
1.278
1.222
1.224
1.247
1.178
1.177
1.197
1.142
1.146
1.158
1.084
1.086
1.093
1.053
1.054
1.058
1.389
1.314
1.255
1.203
1.162
1.098
1.061
0.4 M aq u eo u s N aC l solution
1.173
0.9385
0.7508
0.6006
0.4805
0.2803
0.1730
1.310
1.257
1.207
1.164
1.130
1.077
1.048
1.333
1.274
1.220
1.177
1.141
1.085
1.051
1.337
1.276
1.224
1.175
1.144
1.086
1.052
1.356
1.285
1.229
1.180
1.144
1.092
1.056
T able 3. B values (1/m ole) for BaCl 2 solutions in aqueous
N aC l at different tem peratures.
Solvent
35 °C
U
o
O
O
O
U
o
O
w here C is the concentration o f the solute and rj0 the
viscosity o f the solvent. T he constant A is a theoretically
ju stifia b le ion — ion interaction p aram eter, and B is an
em pirical ion - solvent interaction constant w hich can not
be calculated from a m odel [3]. M any single salts have
been studied in a queous m edium [1, 2, 4, 5] and also in
m ixed solvents, b u t there are very few studies o f m ixed
electrolytes in aqueous solution [6, 7],
In existing viscosity studies on m ixed aq u eo u s electro­
lytes the ratio o f the concentrations o f the electrolytes was
kep t constant [6, 7], In the present study, sodium chloridew ater m ixtures were considered as solvents and the effect
o f B aC l2 was studied. T he solvents used were 0.2, 0.3 and
0.4 m olar in N aC l.
B arium chloride (G R ) and sodium chloride (A R ) were
from BDH, India, and were used w ithout fu rth er p u rific a ­
tion. T he w ater used was double distilled. An O stw ald
viscom eter w ith a flow tim e o f 213 sec for w ater at 30 °C
was used. T he viscom eter and the 10 ml pyknom eter were
cleaned with alkali, sulphuric acid and distilled w ater, in
th a t order, before use. T he tem p eratu re o f the b a th was
controlled to ± 0.02 °C.
T ables 1 and 2 show the experim ental results. O n fitting
(1) to these, in accordance w ith [8] very low positive values
o f A w here found, show ing th at the solute - solute in te r­
actions are small. T he B values o btained by fitting a
stra ig h t line to the d a ta are presented in T able 3. T he B
value for BaCl2 in w ater at 35 °C was found to be
0.282 1/mole (literature value 0.285 [9, 10]).
C o f BaCl2
(m oles/liter)
IT)
(1)
0.547
0.556
0.561
0.568
T able 2. R elative viscosities w/«0 o f solutions o f BaCl-> in
a queous N aC l at different tem peratures.
U
o
= 1+ A ^ C + B C ,
0.596
0.598
0.603
0.617
U
o
A ccording to Jones and D ole [1,2] the viscosity rj o f
electrolyte solutions follows the em pirical relation
0.653
0.660
0.665
0.672
O
Viscosities o f the title solution were m easured at 35,
40, 45 and 50 °C for 0.2, 0.3 and 0.4 M N aC l and 7 B aC l2
concentrations. C onsidering the N aC l solutions as the
solvents for B aCl2, the results w ere com pared w ith the
Jones-D ole equation, the M oulik equation and the Vand
equation.
0.719
0.733
0.738
0.752
U
o
Z. N aturforsch. 4 2 a , 9 0 3 -9 0 4 (1987);
received A pril 23, 1987
M
M
M
M
O
0.0
0.2
0.3
0.4
D e p artm en t o f C hem istry, Faculty o f Science,
M. S. U niversity o f B aroda, B aroda, India
40 °C
U
o
Solvent
Animesh K um ar Rakshit
n
T able 1. Viscosities (cp) o f a q u eo u s sodium chloride solu­
tions at different tem peratures.
T h e V isc o sity o f A q u eou s B a C l2 + N aC l
S o lu tio n s *
%
903
0.2 M N aC l
0.3 M N aC l
0.4 M N aC l
0.301
0.283
0.260
0.318
0.301
0.279
0.333
0.315
0.293
0.344
0.327
0.306
T he results m ay be su m m arized q u alitatively as follows:
* A m ajor p a rt o f this work was done at the C hem istry
Section. U D C T , the U niversity o f Bom bay, Bom bay,
India.
R e p rin t request to Dr. A. K. R akshit, D e p artm en t o f
C hem istry, Faculty o f Science, M .S. U niversity o f B aroda,
B aroda, India.
(i)
T he viscosities increase w ith increasing N aC l and
B aC l2 concentrations, w hich im plies rj > r/0, and d e ­
crease w ith increasing tem perature.
(ii) ij/ris increases w ith increasing tem perature.
(iii) The increase o f rj w ith increasing B aC l2 concentration
is the sm aller the larger th e N aC l concentration.
0932-0784 / 87 / 0800-0903 $ 01.30/0. - Please o rd e r a re p rin t ra th e r th an m aking y our own copy.
Unauthenticated
Download Date | 6/17/17 6:28 PM
N otizen
904
T able 4. P aram eters o f (2) and (4) for a q u eo u s B aC l2N aC l solutions.
T em p. °C
M oulik Eq. (2)
tion o f the ions decreases w ith increasing concen tratio n o f
the ions.
A ccording to M oulik [11], for concentrated solutions
V and Eq. (4)
(.r,/ri0) 2 = I + M C 2 ,
/
35
40
45
50
35
40
45
50
1.158
1.174
1.182
1.189
1.160
1.160
1.181
1.189
M
[(1/m ole)2]
B aC l2-0.2 M N aC l
0.522
0.556
0.585
0.602
B aC l2-0.3 M N aC l
0.506
0.522
0.560
0.579
V° (extrapolated)
[cm V m ole]
120.38
129.60
138.34
145.81
1.152
1.164
1.166
1.168
0.449
0.485
0.491
0.521
2.5 0
In
(3)
\ - Q 0 '
121.01
123.15
134.15
140.55
w here Q is a generalized p article in te rac tio n coefficient
and 0 the volum e fraction o f the solute. A re arra n g em en t
o f (3) gives
2.5 C
B aC l2-0.4 M N aC l
35
40
45
50
(2)
w here / and M are constants. Plots o f rj2x vs. C 2 w ere done,
and the com puted values o f / and M are given in T ab le 4.
T he correlation coefficients (0.96 - 0.98) w ere found to be
not as good as for rj vs. C plots (0.992 —0.996).
Vand [12] suggested the equation
109.80
118.48
121.11
127.49
Possible explanation: T he viscosity increases w ith in­
creasing solvation o f the ions. T hen (ii) w ould show th at
the solvation o f B a2+ is less tem p e ra tu re d ep en d en t th an
the solvation o f N a +, and (iii) w ould show th at the solva­
[1] G. Jones and M. D ole, J. A m er. C hem . Soc. 51, 2950
(1929).
[2] G. Jones and S. T alley, J. A m er. C hem . Soc. 55, 624
(1933).
[3] R. W. G urney, T onic Processes in Solution, D over
P ublication Inc., N ew Y ork 1953.
[4] R. D ordick, L. K orson, and W. D rost-H ansen, J. Coll.
Interface Sei. 72, 206 (1979).
[5] S. P. M oulik and A. K. R akshit, J. Ind. C hem . Soc.
52,450 (1975).
[6] P. K. M andal, B. K. Seal, and A. S. Basu, Z. Phys.
C hem ie L eipzig 258,809 (1977).
[7] P. K. M andal, B. K. Seal, and A. S. Basu, Z. Phys.
C hem ie L eipzig 260,193 (1979).
1
2.303 lo g W vo)
(4)
w here V is the partial m olar volum e o f the solute. O n
plotting the 1. h.s. o f (4) vs. C, reasonable straig h t lines
w ere obtained (correlation coefficient 0.95 to 0.996). T he
intercepts with the ord in ate gave the F° values o f T ab le 4.
B values calculated w ith the equation
B [1/mole] = 2.5 • 10~3 K° [cmVmole]
(5)
did not tally with the B values o f T ab le 3 b u t w ere o f the
sam e order o f m agnitude, as has been found for o th e r
system s [14] too.
[8] C. Q uintana, M. L. L lorenta, M. Sanchez, and A.
Vivo, J. C hem . Soc., F a ra d ay T rans I 82, 3307 (1986).
[9] A. S. C hakravarty and B. Prasad, T rans. F a ra d a y Soc.
35,1466 (1939).
[10] M. K am insky, Discuss. F a ra d a y Soc. 24,171 (1957).
[11] S. P. M oulik. J. Phys. C hem . 72,4682 (1968).
[12] V. Vand, J. Phys. Coll. C hem . 52 ,2 7 7 (1948).
[13] J. E. D esnoyers and G. Perrin, J. S olution C hem . 1,
199 (1972).
[14] Vishnu and V. K. Singh, Ind. J. C hem . 2 0 A , 24
(1981).
Unauthenticated
Download Date | 6/17/17 6:28 PM