Table IV. Comparison of Results with Those Obtained by Bloom and Tricklebank ( 7 )
Fraction CdC1?
0 0.3
0.5 0.7
1.0
H,?, - H,,,, Kcal. Mole
This work 16.08 16.39 16.75 17.09 17.74
Ref. (I)
15.60 15.75 16.10 16.70 17.25
Hv
HI,,,, Kcal.: Mole
This work 17.41 17.76 18.10 18.45 19.04
-
Ref. (I)
16.65 17.05 17.40 17.80 18.25
Table
V. Comparison of Heat Capacity Determinations Temp. Range,
H > ?-, H,n, Kcal. Mole
This work 18.74 19.12 19.44 19.80 20.34
Ref. (I)
17.80 18.30 18.70 18.90 19.30
indicate the properties calculated assuming ideal solutions. Figure 1 shows that the enthalpy of mixing in this system is less than 200 cal. per mole. The entropy data indicate that the entropy of mixing is ideal assuming random mixing of the lead and cadmium ions. Boardman, Darman, and Heymann (2) found negative deviations from additivity in molar volumes for the CdCl PbC1. system. An exothermic enthalpy of mixing is expected t o be associated with this result. T h e enthalpy d a t a of Figure 1 indicate small negative deviations from ideality, a trend also reported by Bloom and Tricklebank (I). The enthalpy measurements may be used t o compute molar heat capacities. Assuming t h a t the effect of the change in pressure is negligible, C, was computed from the slope of the curves of enthalpy us temperature. T h e results are summarized in Table V and compared with those of Bloom and Tricklebank ( I ) , Kelley (6), and Topol and Ransom (11). The latter work was limited to a temperature range 60" to 100°K. above and below the melting point of CdCL. T h e range of possible error must be increased for the C, values, since differences must be taken in the calorimetric values and temperatures in determining slopes. The error in C, was taken as 3%, double that of the enthalpy values. T h e values agree well with those suggested by Kelley (6) and with the value for liquid CdCL reported by Topol and Ransom (11). T h e values reported by them for solid CdCl, seems high which may account for their
OK. PbC1, (solid) PbCl, (liquid) CdCl? (solid) CdC1, (liquid)
300-773 774-963 300-840 841-958
This work 20.4 26.6 19.7 26.6
C,,, Cal.: Mole - K. Ref. Ref. (1)
(6)
19.8 22.6 18.9 21.8
20.2" 27.2 20.2b
. .,
Ref. (I!) .
.
I
... 28.5' 26.3'
"Average value from C,v = 15.96 + 8 x 10 'T. 'Average value from C, = 14.54 + 9.6 x 10 IT. 'Temperature range 60" to 100"K. above and below the melting point.
somewhat lower enthalpy of fusion. The agreement between these values and those of Bloom and Tricklebank ( 1 ) for solid PbC12 and CdClr is satisfactory. LITERATURE CITED
S.B., Australian J . Chem. 19, 18796 (1966). Boardman. S.K., Darman, H . , Heymann. E.. J . 1'h.w. C ' ( ~ i / ~ i d ('hem. 53. 375-82 (19191. Furukawa, G. T., Ginnings, D. C., McCoskey, R. E., Kelson, R. A , , J . Res. Natl. Bur. Std. 46 ( 3 ) ,195-206 (1951). Hagemark, K., Hengstenberg, D., J. CHEM.ENG.DATA11 (4), 596-8 (1966). Jessup, R. S., J . Res. Natl. Bur. Std. 55, 317-22 (1955). Kelley, K. K., U . S . Bur. Mines, Bull. 584 (1960). Kleppa, 0. J., J . Phys. Chem. 64, 1937-40 (1960). Kurtz, P., Ph.D. dissertation, University of California at Los Angeles, Los Angeles, Calif., 1964. Levin, E. M., Robbins, C. R., McMurdie, H. F., "Phase Diagrams for Ceramists," p. 397, Am. Ceram. SOC.Inc., 1964. Morris, J. P., Foerster, E. F., Schultz, C. W'., Zellars, G. R., C:. S . Bur. Mines, Rept. Inuest. RI 6723 (1966). Topol, L. E., Ransom, L. D., J . P h p Chem 64, 1339-40 (1960).
(1) Bloom, H., Tricklebank,
(21 (3)
(4) (5) (6) (7)
(8) (9) (10) (11)
RECEIVED for review May 2 2 , 1967. Accepted September 24, 1967.
Surface Tensions of Water-Methyl Ethyl Ketone Mixtures ROBERT B. ROEMER' a n d GEORGE LEPPERT Department of Mechanical Engineering, Stanford University, Stanford, Calif. 94305
Surface tensions of water and methyl ethyl ketone mixtures are reported for concentrations from 0 to 10 weight YO of methyl ethyl ketone and for temperatures from 20' to 6 O o C . The surface tensions, measured by the maximum bubble pressure method, were determined for use in analyzing boiling heat transfer data.
V A R I O U S investigators discovered that the addition of certain volatile organic components to water affects the nucleate boiling process, especially the critical heat flux a t which nucleate boiling fails and film boiling begins (6, 7, 9). Van Wijk, Vos, and von Stralen (9) experimented with several substances and found that methyl ethyl ketone (M.E.K.) increased the critical flux from heated wires by as much as 230';. Tests by Pitts and Leppert (7) also Present address: University of California, Santa Barbara, Calif.
28
show an increase in the critical flux, but those of Owens (6) with larger diameter heaters did not show this effect. Leppert, Costello, and Hoglund (5) reported on nucleate boiling and observed the pronounced effect of additives on bubble size and frequency. EXPERIMENTAL Materials. The water was doubly distilled and the M.E.K. was Eastman Kodak reagent grade. Reagent grade M.E.K.
JOURNAL OF CHEMICAL AND ENGINEERING DATA
Table I. Surface Tensions of Water-Methyl
Temu..
c:
h'eieht M.E.K.
26.0 26.2 26.6 26.6 37.2
0.63 0.63 0.63 0.63 0.71
:37,2 47.t5
0.71
37.5 26.8 26.8 27.0 27.0 38.3 38.4 38.5 38.5 57.0 57.0 5i.l 57.1 57.1 22.4 22.4 22.4 7,l 6 22.6 29.5 29.5 29.6 29.6 40.7 40.7 40.6 40.5 50.9 50.9 50.9 50.9 27.1 27.1 27.1 27.1
' (
Surface Tension. Dyne! Cm.
0.71 0.71 1.17 1.17 1.17
1.17 1.17 1.17 1.17 1.17 1.23 1.23 1.23 1.23 1.23 1.95 1.95 1.95 1.95 1.95 2.01 2.01 2.01 2.01 1.9,; 1.95 1.9j 1.95 1.95 1.95 1.95 1.95 4.12 4.12 4.12 4.12
65.68 65.36 65.40 65.36 63.74 63.78 63.90 63.90 61.89 61.77 61.61 61.53 59.84 59.87 59.80 59.72 57.47 57.47 57.55 57.55 57.62 57.07 57.07 56.68 56.84 56.64 55.65 55.65 55.97 56.05 54.47 54.55 54.59 54.59 53.48 53.52 53.48 53.36 49.77 49.73 49.77 49.73
Average Wt. '/
. JOURNAL OF CHEMICAL AND ENGINEERING DATA
