Page 211 - Modern physical chemistry

References 203

8.26 Calculate the activity of the hydrogen ion in a solution 0.0100 m in HCI and 0.0150 m in NaCl.
8.27 Calculate mw in a solution 0.0100 m in fonnic acid and 0.100 m in KCl.
8.28 Calculate mw in a solution 0 100 m in KCI and 0.0100 m in glycine.
8.29 Calculate ~+ in 0.0100 m ammonium formate.
8.30 If saturated aqueous NaCI is 6.12 m and has a solubility product of 38.42 m 2 , what is (a) the
activity of the electrolyte, (b) the mean ionic activity, and (c) the mean ionic activity coef-
ficient in the saturated solution?
8.31 The solubility of CU(l03)2 in aqueous solutions of KCI was determined at 25 0 C with the
results in table 8.B.

TABLES.B
KCl Cu(IOsJ:e
Concentration, m Solubility, m
0.00000 0.003245
0.00501 0.003398
0.01002 0.003517
0.02005 0.003730
0.03511 0.003975
0.05017 0.004166
0.07529 0.004453
0.1005 0.004694

For each solution calculate J.l and the m. of CU(I03)2' Then plot log m. against {ji and (a)
extrapolate linearly to infinite dilution to find an approximate log K, (b) extrapolate the
curve to infinite dilution to obtain a better log K.
8.32 (a) From the graph for problem 8.31, obtain log m. for a solution whose ionic strength is 0.100,
Then calculate the corresponding mean ionic activity coefficient. (b) From tables 8.5 and 8.6,
obtain the mean ionic activity coefficient for CU(I0J2 in a solution of ionic strength 0.100.

References
Books
Harned, H. S., and Owen, B. B.: 1958, The Physical Chemistry oj Electrolytic Solutions, 3rd ed.,
Reinhold, New York, pp. 1-764.
This is a comprehensive text on properties of electrolytic solutions. The classic theories
are presented in detail. Extensive experimental data is summarized in the tables.
Horvath, A L.: 1985, Handbook oj Aqueous Electrolyte Solutlons, John Wiley & Sons, New York,
pp. 206-232.
Horvath summarizes the methods for estimating, predicting, and correlating physical
properties of aqueous electrolyte solutions. Chapter 2.8 is devoted to ionic activity coeffi-
cients. Appropriate references are cited.
Meites, L.: 1981, An Introduction to Chemical Equilibrium and Kinetics, Pergamon, New York,
pp. 8-32, 7~212.
Here we have a low level presentation of chemical thermodynamics and its application to
equilibria. Solubilities of molecular and ionic compounds, acid-base reactions, and
complex formation are all discussed in considerable detail.
Pitzer, K. S. (editor): 1991, Activity Co~ents in Electrolyte Solutions, CRC Press, Boca
Raton, FL (abbreviated AC).