- Email: [email protected]
Vapour pressure of liquid xenon
P h y s i c a X V I , no. 3
Maart
1950
VAPOUR PRESSURE OF LIQUID XENON by A. MICHELS and T. WASSENAAR 104th publication of the Van der Waals Fund. Van der Waals Laboratory, Gemeente Universiteit, Amsterdam Summary
The vapour pressure of liquid xenon has been measured between --110 ° and + 16°C. The results are represented as a function of temperature by a formula, containing four constants.
§ 1. Introduction. The vapour pressure of liquid xenon has been measured between --110°C and +16°C, covering the pressure range from 0.8 to 57 atm. The method and apparatus have been described in previous papers 1) ~). Xenon was placed at our disposal by the Laboratory for Scientific Research of the Philips Works, Eindhoven. For a final purification the following technique was used. Xenon was crystallized at liquid air temperature and traces of residual gas were pumped off, first with a vacuum pump and in second instance by adsorption on silica gel cooled with liquid nitrogen. Xe was then distilled at pressures round atmospheric, the first and last fractions being discarded. This was repeated four times till the vapour pressure at constant temperature did not vary more than 1 mm Hg during fractionation. § 2. Results. The results are given in table I; in fig. 1 the logarithm of the pressure is plotted against lIT. The constants of the equation t ° l o g P = A / T + B I°log T + CT + D to fit the experimental results have been calculated with the method of least squares. Their values are A
=
B =
-
-
-
-
1040.76
C =
+
0.0085216
8.25369
D =
+
23.20334.
--
253
-
-
254
A. MICHELS
A N D T. W A S S E N A A R
Pressures calculated with this equation from the experimental temperatures are compared with the pressures, as measured, in table I. Fig. 2 shows the differences and their deviations from a smooth curve. TABLE
I
V a p o u r p r e s s u r e of X e n o n
Pexp. a t m .
T°K
0.82229 0.85405 0.85410 0.91643 0.91702 0.94194 0.96576 0.96562 0.98167 0.99603 1.01111 1.06018 1.77188 2.25216 2.72667 3.35252 3.36936 3.65885 3.89820 3.95761 5.3899 6.0128 7.0783 8.5094 11.6901 14.0562 17.9371 22.3117 25.3103 29.8433 34.7593 41.4019 44.7817 49.6466 53.3871 55.0868 56.2289 56.9917
161.69 o 162.328 162.331 163.529 163.531 163.99 o 164.426 164.427 164.705 164.953 165.21~ 166.052 175.644 180.56 s 184.70 a 189.40 v 189.532 191.48 o 193.01 s 193.38 x 201.20 o 204.12 o 208.65~ 214.018 223.95~ 230.156 238.875 247.20s 252.26~ 259.16o 265.824 273.833 277.53 z 282.494 286.01 o 287.53 o 288.529 289.18 o
Pca~. a t m . 0.82205 0.85367 0.85381 0.91649 0.91668 0.94191 0.96590 0.96598 0.98177 0.99580 l.Oll09 1.06030 1,77109 2.25185 2.72690 3.35490 3.37280 3.66269 3.90400 3.96223 5.3911 6.0113 7.0742 8.4989 11.6729 14.0346 17.9201 22.2977 25.3023 29.8648 34.7985 41.4887 44.8725 49.7244 53.3949 55.0453 56.1423 56,8814
Pexp.--Pcalc. + 0.0002 + 0.0004 + 0.0003 --0.0001 + 0.0003 0.0000 --0.0001 --0.0004 --0.0001 + 0.0002 0.0000 --0.0001 + 0.0008 + 0.0003 --0.0002 --0.0024 --0.0034 --0.0038 --0.0058 --0.0046 --0.0012 40.0015 + 0.0041 +0.0105 +0.0172 +0.0216 40.0170 +0.0140 + 0.0080 --0.0215 --0.0392 --0.0868 --0.0908 --0.0778 --0.0078 +0.0415 + 0.0866 + 0 . I 103
VAPOUR PRESSURE OF LIQUID XENON
255
§ 3. Comparison with other measurements. T h e m e a s u r e m e n t s described in t h e l i t e r a t u r e can be d i v i d e d in t w o groups, those r o u n d a n d below a t m o s p h e r i c a n d those at higher pressures. T h e l a t t e r Io 9 P
P
x¢
\
~otm 30
\
20
\
IO
--
$
0.$
0
3.5
4
I
27a
ZSO
~
4.5
ZOO
~
.~
,
175°K
Fig. 1. The log 'of the vapour pressure as a function of 1/7". • present measurements. (~) da,t a o f C l u s i u s and W e i g a n d . [] d a t a o f P a t t e r s o n , Cripps and W h y t l a w - G r a y . Pc.p.- P¢olc.
0
170
180
200
220
Z 40
-0.1
Fig. 2. The difference between experimental and calculated pressures as a function of T. include d a t a of C I u s i u s a n d W e i g a n d 3) w h o claim an accur a c y of the o r d e r of 0.5 a t m . Fig. 1 shows an a g r e e m e n t w i t h the p r e s e n t m e a s u r e m e n t s within these limits. O t h e r d a t a , those of Patterson, Cripps and Whytlaw-Gray4), are also i n s e r t e d in figure l, t o g e t h e r w i t h t h e i r v a l u e of the critical point t,, = -}- 16.6°C
P, = 58.22 a t m .
256
V A P O U R P R E S S U R E OF L I Q U I D X E N O N
For comparison of the low-pressure data with those of other authors the boiling point and the triple point have been chosen. Use was made of the formula together with the deviation curve. The results are given in table II. T A B L E II t b °C Peters and W e i l l 6 ) . --108.6 + Allen and M o o r e 6) . --107.1 4Heuse and O t t o 7) --108.02 + Clusius B) . this publication . . . . . --108.12 4-
Ptr
ttr °C 0.5 --112.0 0.3 --111.5 0.05--111.85 --111.80 0.01
44+ ±
exp. 0.5 0.5 0.05 0.03
calc.
61.55 cm 60.0 60.62 61.02 4- 0 . 1 8 e m 61.22 61.20 -4- 0.11 i
Values of the triple point pressure given in the last column of table II were calculated by substitution of the experimental triple point temperature in the formula. This involves a small extrapolation. C 1 u s i u s' value s) for the critical pressure is in excellent agreement with the calculated pressure, whereas H e u s e and O t t o's value 7) is 0.4 cm Hg lower. This corresponds to a temperature difference of 0.1°C in agreement with a discrepancy of the boiling point values. Received 23-12-49
REFERENCES 1) 2) 3) 4) 5) 6) 7) 8)
A. M i c h e l s andT. Wassenaar, Physica 14, 104, 1948. A. M i c h e l s andT. Wassenaar, Physica 16,000, 1950. K. C l u s i u s and K. W e i g a n d , Zs. phys. Chem. B 4 2 , II1, 1939. H. P a t t e r s o n , R. C r i p p s andR. Whytlaw-Gray, Proe. Roy. Soc. 86, 579, 1912. K. P e t e r s and K. W e i l l , Zs. phys. Chem. A 1 4 8 , 2 7 , 1930. T. A l l e n and R. M o o r e , J. Am. Chem. Soc. 5 3 , 2 5 2 2 , 1931. W. H e u s e and J. O t t o , Zs. techn. Phys. 18,277, 1932. K. C l u s i u s , Zs. phys. Chem. B 5 0 , 4 0 3 , 1941.
Maart
1950
VAPOUR PRESSURE OF LIQUID XENON by A. MICHELS and T. WASSENAAR 104th publication of the Van der Waals Fund. Van der Waals Laboratory, Gemeente Universiteit, Amsterdam Summary
The vapour pressure of liquid xenon has been measured between --110 ° and + 16°C. The results are represented as a function of temperature by a formula, containing four constants.
§ 1. Introduction. The vapour pressure of liquid xenon has been measured between --110°C and +16°C, covering the pressure range from 0.8 to 57 atm. The method and apparatus have been described in previous papers 1) ~). Xenon was placed at our disposal by the Laboratory for Scientific Research of the Philips Works, Eindhoven. For a final purification the following technique was used. Xenon was crystallized at liquid air temperature and traces of residual gas were pumped off, first with a vacuum pump and in second instance by adsorption on silica gel cooled with liquid nitrogen. Xe was then distilled at pressures round atmospheric, the first and last fractions being discarded. This was repeated four times till the vapour pressure at constant temperature did not vary more than 1 mm Hg during fractionation. § 2. Results. The results are given in table I; in fig. 1 the logarithm of the pressure is plotted against lIT. The constants of the equation t ° l o g P = A / T + B I°log T + CT + D to fit the experimental results have been calculated with the method of least squares. Their values are A
=
B =
-
-
-
-
1040.76
C =
+
0.0085216
8.25369
D =
+
23.20334.
--
253
-
-
254
A. MICHELS
A N D T. W A S S E N A A R
Pressures calculated with this equation from the experimental temperatures are compared with the pressures, as measured, in table I. Fig. 2 shows the differences and their deviations from a smooth curve. TABLE
I
V a p o u r p r e s s u r e of X e n o n
Pexp. a t m .
T°K
0.82229 0.85405 0.85410 0.91643 0.91702 0.94194 0.96576 0.96562 0.98167 0.99603 1.01111 1.06018 1.77188 2.25216 2.72667 3.35252 3.36936 3.65885 3.89820 3.95761 5.3899 6.0128 7.0783 8.5094 11.6901 14.0562 17.9371 22.3117 25.3103 29.8433 34.7593 41.4019 44.7817 49.6466 53.3871 55.0868 56.2289 56.9917
161.69 o 162.328 162.331 163.529 163.531 163.99 o 164.426 164.427 164.705 164.953 165.21~ 166.052 175.644 180.56 s 184.70 a 189.40 v 189.532 191.48 o 193.01 s 193.38 x 201.20 o 204.12 o 208.65~ 214.018 223.95~ 230.156 238.875 247.20s 252.26~ 259.16o 265.824 273.833 277.53 z 282.494 286.01 o 287.53 o 288.529 289.18 o
Pca~. a t m . 0.82205 0.85367 0.85381 0.91649 0.91668 0.94191 0.96590 0.96598 0.98177 0.99580 l.Oll09 1.06030 1,77109 2.25185 2.72690 3.35490 3.37280 3.66269 3.90400 3.96223 5.3911 6.0113 7.0742 8.4989 11.6729 14.0346 17.9201 22.2977 25.3023 29.8648 34.7985 41.4887 44.8725 49.7244 53.3949 55.0453 56.1423 56,8814
Pexp.--Pcalc. + 0.0002 + 0.0004 + 0.0003 --0.0001 + 0.0003 0.0000 --0.0001 --0.0004 --0.0001 + 0.0002 0.0000 --0.0001 + 0.0008 + 0.0003 --0.0002 --0.0024 --0.0034 --0.0038 --0.0058 --0.0046 --0.0012 40.0015 + 0.0041 +0.0105 +0.0172 +0.0216 40.0170 +0.0140 + 0.0080 --0.0215 --0.0392 --0.0868 --0.0908 --0.0778 --0.0078 +0.0415 + 0.0866 + 0 . I 103
VAPOUR PRESSURE OF LIQUID XENON
255
§ 3. Comparison with other measurements. T h e m e a s u r e m e n t s described in t h e l i t e r a t u r e can be d i v i d e d in t w o groups, those r o u n d a n d below a t m o s p h e r i c a n d those at higher pressures. T h e l a t t e r Io 9 P
P
x¢
\
~otm 30
\
20
\
IO
--
$
0.$
0
3.5
4
I
27a
ZSO
~
4.5
ZOO
~
.~
,
175°K
Fig. 1. The log 'of the vapour pressure as a function of 1/7". • present measurements. (~) da,t a o f C l u s i u s and W e i g a n d . [] d a t a o f P a t t e r s o n , Cripps and W h y t l a w - G r a y . Pc.p.- P¢olc.
0
170
180
200
220
Z 40
-0.1
Fig. 2. The difference between experimental and calculated pressures as a function of T. include d a t a of C I u s i u s a n d W e i g a n d 3) w h o claim an accur a c y of the o r d e r of 0.5 a t m . Fig. 1 shows an a g r e e m e n t w i t h the p r e s e n t m e a s u r e m e n t s within these limits. O t h e r d a t a , those of Patterson, Cripps and Whytlaw-Gray4), are also i n s e r t e d in figure l, t o g e t h e r w i t h t h e i r v a l u e of the critical point t,, = -}- 16.6°C
P, = 58.22 a t m .
256
V A P O U R P R E S S U R E OF L I Q U I D X E N O N
For comparison of the low-pressure data with those of other authors the boiling point and the triple point have been chosen. Use was made of the formula together with the deviation curve. The results are given in table II. T A B L E II t b °C Peters and W e i l l 6 ) . --108.6 + Allen and M o o r e 6) . --107.1 4Heuse and O t t o 7) --108.02 + Clusius B) . this publication . . . . . --108.12 4-
Ptr
ttr °C 0.5 --112.0 0.3 --111.5 0.05--111.85 --111.80 0.01
44+ ±
exp. 0.5 0.5 0.05 0.03
calc.
61.55 cm 60.0 60.62 61.02 4- 0 . 1 8 e m 61.22 61.20 -4- 0.11 i
Values of the triple point pressure given in the last column of table II were calculated by substitution of the experimental triple point temperature in the formula. This involves a small extrapolation. C 1 u s i u s' value s) for the critical pressure is in excellent agreement with the calculated pressure, whereas H e u s e and O t t o's value 7) is 0.4 cm Hg lower. This corresponds to a temperature difference of 0.1°C in agreement with a discrepancy of the boiling point values. Received 23-12-49
REFERENCES 1) 2) 3) 4) 5) 6) 7) 8)
A. M i c h e l s andT. Wassenaar, Physica 14, 104, 1948. A. M i c h e l s andT. Wassenaar, Physica 16,000, 1950. K. C l u s i u s and K. W e i g a n d , Zs. phys. Chem. B 4 2 , II1, 1939. H. P a t t e r s o n , R. C r i p p s andR. Whytlaw-Gray, Proe. Roy. Soc. 86, 579, 1912. K. P e t e r s and K. W e i l l , Zs. phys. Chem. A 1 4 8 , 2 7 , 1930. T. A l l e n and R. M o o r e , J. Am. Chem. Soc. 5 3 , 2 5 2 2 , 1931. W. H e u s e and J. O t t o , Zs. techn. Phys. 18,277, 1932. K. C l u s i u s , Zs. phys. Chem. B 5 0 , 4 0 3 , 1941.