Physical Chemistry Third Edition

1226 A Tables of Numerical Data

Table A.11 Mean Ionic Activity Coefficients of Aqueous Electrolytes at 25◦C

Molality 0.1 0.2 0.5 1.0 1.6 2.5

1–1 Electrolytes

Debye–

Hückel

0.754 0.696 0.615 0.556 0.519 0.487

Davies 0.781 0.747 0.733 0.791 0.912 1.175

HCl 0.796 0.767 0.757 0.809 0.916 1.147

NaOH 0.764 0.725 0.688 0.677 0.690 0.741

NaCl 0.778 0.735 0.681 0.657 0.655 0.688

KCl 0.770 0.718 0.649 0.604 0.580 0.569

Sodium

acetate

0.791 0.757 0.735 0.757 0.809 0.914

NH 4 NO 3 0.740 0.677 0.582 0.504 0.447 0.391

1–2 and 2–1 Electrolytes

Debye–

Hückel

0.436 0.359 0.275 0.226 0.199 0.179

Davies 0.538 0.547 0.790 1.868 5.865 35.27

MgCl 2 0.528 0.488 0.480 0.569 0.802 1.538

Na 2 SO 4 0.452 0.371 0.270 0.204 0.168 0.144

K 2 CrO 4 0.466 0.356 0.298 0.240 0.212 0.194

2–2 Electrolytes

Debye–

Hückel

0.162 0.109 0.064 0.044 0.035 0.026

Davies 0.284 0.336 1.069 12.24 284.5 −

CuSO 4 0.150 0.104 0.0620 0.0432 −−

ZnSO 4 0.150 0.104 0.0630 0.0435 0.0363 0.0367

CdSO 4 0.150 0.103 0.0615 0.0415 0.0338 0.0317

From R. A. Robinson and R. H. Stokes,Electrolyte Solutions, 2nd ed., Butterworths, London, 1968.

Table A.12 Partial Vapor Pressure of Hydrogen Halides in

Aqueous Solution at 298.15 K

Pressure/torr

Molality/mol kg−^1 HCl HBr HI

4. 0 0.0182

5. 0 0.0530

6. 0 0.140 0.00151 0.00057

7. 0 0.348 0.00370 0.00182

8. 0 0.844 0.0089 0.0065

9. 0 1.93 0.0226 0.0295

10. 0 4.20 0.059 0.132

11. 0 0.151

From S. J. Bates and H. D. Kirschman,J. Am. Chem. Soc., 41 , 1991 (1919).