Another Electrolyte Solution Example
The following data are available for the mean ionic activity coefficient of sodium chloride in water at 25°C.
| Molality | \gamma_{\pm} | Molality | \gamma_{\pm} |
| 0.0 | 1.00 | 2.0 | 0.669 |
| 0.1 | 0.778 | 3.0 | 0.714 |
| 0.25 | 0.72 | 4.0 | 0.782 |
| 0.5 | 0.681 | 5.0 | 0.873 |
| 0.75 | 0.665 | 6.0 | 0.987 |
| 1.0 | 0.657 | ||
a. Compare the predictions of the Debye-Huckel limiting law with these data:
\ln \gamma_{\pm}=-1.178 \sqrt{I} (1)
where I is the ionic strength.
b. Compare the predictions of the following version of the extended Debye-Huckel limiting law with these data.
\ln \gamma_{\pm}=-\frac{1.178 \sqrt{I}}{1+\sqrt{I}} (2)
c. Correlate the data with the following expression, in which δ is an adjustable parameter.
\ln \gamma_{\pm}=-\frac{1.178 \sqrt{I}}{1+\sqrt{I}}+\delta I (3)
