I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
320
TABLE XXXIV.
STABILITY A S D CORROSION O F CALCIUM PERIIANGANATE SOLUTIONS AT
Control - E2 El Piessure, atm. 0 day 1 day. 5 days 10 days 19 days 21 days 56 days h.InOa-, % Original Final Change Vol. of tube, ml. Weight, grams Initial Final Change a
1.0 1.0 1.0 1.0 1.0 1.0
...
1.0 0.9 1.0 1.0 1.0 0.9 1.0
51.9 52.1 10.2 12.5
51.9 53.5 +1.6 10.5
ITD1010 -Al--^-'
A I , 2S'/aH -___€31
BZ
1.0 0.9 0.9 0.9 0.9 0.9
1.0 1.0 0.9 1.0 1.0 1.0
1.0 1.0 1.0 1.0 1.0 1.0 1.0
51.9 51.1 -0.8 9.43
5f.9 01.3 -0.6 8.87
A2
...
1.0 1.0 0.9 0.9
0.9 1.0 1.0
61.9 51.3 -0.6 9.02
.51,9 51.2 -0.7
2.7508 2.7511 + 0 , 0003
2,7783 2.7763 +0.0008
8.93
...
1.0579 1,0579 0.0000
1.0575 1,0574 -0.0001
SS Type 304 -~--C1 c2 1.0 1.0 0.9 0.9 1.0 1.0
...
51.9 51.0 -0.9 8.48
O
Bakelite" D1 D2
2.8946 2.8948
+0.0002
-
1.0
0.9 1.0 1.0 1.0
1.0
1.0
1.0 1.0
1.0
1.0 1.0
...
51.9 51.7 -0.2 12.69
2.9235 4.9235 0.0000
50 C.
1.0
1.0 1.0 1.0 1.0 1.0 1.0 1.0
Vol. 38, No. 3
51.9 51.7
51.9 51.8 -0.1 12.77
-c.2
12.55 4.596G 4.5970 4-0.0004
4 . G255 4.6259
-to.0004
Steel test piec:es coated according to CWB, Specification 196-131-207.
TABLExxxv. TESTO F
\rARIOUS ;\IArERIALS I N 5 1 f L . O F CONCEKTRATED CALCIUM PER\lANGANATE SOLT7TIOS AT ROoX
Koroseal and polyethylene are suitable for gaskets and similar applications. Phosphates are thc best stabilizers of those tested. There appears to be a maximum concentration above which a stabilizer ceases to function. Concentrated peroxide is insensitive to shock. Concentrated calcium permanganate solutions are stable a t temperature up to at least 50" C. Ordinary steel containers may be used for its storage and shipment.
TEMPERATURE IN COVERED TESTTUBE Wt. Initial, grams 0.2376
after 7 Daysa _ _ Wt, _ _ _after _ ~ - 28 Daysa Final, Change, Initial, Final, Change, mg. grams grams grams mg. 0,2375 -0.1 0,2091 0,2093 +0.2
Garlock 7790 Saran tubing Clear 0.5264 0.5265 +O.l 0.4954 0.4957 Dark 0.6333 0.6331 -0.2 0 , 6 0 2 7 0,6028 Koroseal 117 0.9546 0.9538 -0.8 0.8250 0.8748 2s Alb 0.9486 0,9487 4-0.1 0.9523 0 , 9 5 2 6 +0.2 1.4229 1.4233 SS 446O 1.4152 1.4154 a Test pieces were approximately 0.2 X 0.7 X 2.9 cm. b Aluminum was given Becco treatment. C Stainless steel was pickled i n 10% HzSOa a t 80' C.
4-0.3 +O.l
-0.2 +0.3 +0.4
LlTERATURE CITED
(I) Gilbert, H. N., and Reichert, J. S. (to Du Pont Co.), U. S. Patents 2,001,509 (1935) and 2,091,178 (1937). (2) Maas, O., and co-workers, J. Am. Chem. SOC.,42, 2548-74 (1920) ; 44, 2472-80 (1922); 46, 200-308, 2693-2700 (1924); 51, 674-87 (1929). (3) Reichert, J. S., Chem. Eng. News, 21, 480 (1943). (4) Reichert, J. S.(to Du Pont Co.), U. S. Patent 2,008,726 (1935). (5) Spring, W., 2 . anorg. Ch,em., 8,424-33 (1895). RELEASED b y authority of the Chief, Chemical Warfare Service.
Vapor Pressure-Temperature Nomographs SAMUEL B. LIPPINCOTT AND MARGARET M. LYMAN Esso Laboratories, Standard Oil Development Company, Elizabeth, N . J . Nomographs are presented that give vapor pressure-temperature relations for compounds boiling from -50" to 550' C. If any two of the three related quantities, vapor pressure, temperature, and normal boiling point, are known, the third can be found by a single setting of a straight edge.
THE
need often arises in the laboratory and plant for a rapid method of calculating vapor pressure-temperature relations. A number of nomographs for this purpose have appeared in the literature, but for the most part each nomograph represents only a single class of compounds, and each compound is represented by a given point. The nomographs presented here can be used for all pure liquids boiling between -50' and 560" C. The slide rule for vapor pressure described by Miles ( 2 ) can be applied to a similar range of compounds. The nornographs have the advantage that they do not have to be cut out and mounted before use. Miles gives a complete bibliography of the subject. The nomographs presented here are based upon a method for the correction of boiling points to standard pressure by Hass and Xewton (1). They used a modification of the integrated form of the Clausius-Clapeyron equation: 4
At =
(273.1
+ t)(2.8808 - log p )
+ + 0.15
(2.8808
- log p )
where At =
O
C. to be added to obseTed boiling point
t = observed boiling points, C. 2.8808 - log p = log of observed pressure subtracted
from log of 760 d. = quantity proportional to entropy of vaporization of 760 mm.
Thc solution of this equation is rather laborious and time consuming. First a value for must be determined. For this purpose all compounds are divided arbitrarily into eight groups and listed (Tables I and 11). Substances not included in the tabula,tion may be classified by grouping them with compounds which they resemble closely in physical and structural properties. When the compound has been classified, the value of + can be estimated from a graph in which is plotted against boiling point for each of the eight groups. If the normal boiling point is the unknown, a t least two calculations must be made. The first gives an approximate boiling point; the latter, in turn, is used to obtain a value of + from which to make the more accurate calculxtion. The nornographs (Figures 1 and 2) solve the equation by a single setting of a straight edge. The eight curves through the center of each nomograph represent. the eight groups. The scale along these Eurves gives the normal or standard boiling point a t 760 mm. Thc scale a t the right gives the observed boiling point, and the logarithmic scale a t the left gives the observed pressure.
+
+
INDUSTRIAL AND ENGINEERING CHEMISTRY
March, 1946
E
321
Group
760
-1 -31
c
100
90
-I 0 4
00
70
l
60
0
r" 2 E
E
zl5 . 4
'Oi
G Copyright, 1946,
by S.B.Lipp;nco+t
Figure 1.
Vapor Pressure-Temperature Nomograph for Low-Boiling Compounds
INDUSTRIAL AND ENGINEERING CHEMISTRY
322
Vol. 38, No. 3
Group
4
8
c
LI
E 20
fL
4
,704
15
3 21
~
E
-1
2.5
2 1.5,
k
i Copyright, 1943, by
S.E.Lippinsott
Figure 2.
Vapor Pressure-Temperature Nomograph for High-Boiling
