Section 4: GRAVIMETRIC AND VOLUMETRIC ANALYSIS

4.1 INORGANIC GRAVIMETRIC ANALYSIS

This table gives values of pKw on a molal scale, where Kw is the ionic activity product constant of water. Values are from W. L. Marshall and E. U. Franck, J. Phys. Chem. Ref. Data 10:295 (1981).

Table 4.1: **Ionic Product Constant of Water**
Temp., C	p Kw	Temp., C	p Kw	Temp., C	p Kw
0	14.938	45	13.405	95	12.345
5	14.727	50	13.275	100	12.264
10	14.528	55	13.152	125	11.911
15	14.340	60	13.034	150	11.637
18	14.233	65	12.921	175	11.431
20	14.163	70	12.814	200	11.288
25	13.995	75	12.711	225	11.207
30	13.836	80	12.613	250	11.192
35	13.685	85	12.520	275	11.251
40	13.542	90	12.431	300	11.406

The data refer to various temperatures between 18 and 25 C and were primarily compiled from values cited by Bjerrum, Schwarzenbach, and Sillen, Stability Constants of Metal Complexes, Part II, Chemical Society, London, 1958.

Table 4.2: **Solubility Products**

This table includes the more common reagents used in gravimetric determinations. The lists of elements precipitated are not in all cases exhaustive. The usual solvent for a precipitating agent is indicated in parentheses after its name or formula. When the symbol of an element or radical is italicized, the element may be quantitatively determined by the use of the reagent in question.