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8174919 
Journal Article 
The vapour pressures of nitric acid solutions. Part II. The behaviour of solutes in nitric acid 
Lloyd, L; Wyatt, PAH 
1957 
Yes 
Journal of the Chemical Society
ISSN: 0368-1769 
4268-4274 
English 
The effects of solutes upon the vapour pressure of 100% nitric acid are reported; apart from some measurements with potassium nitrate at 10° and 20°, all determinations were at 0°. The solutes potassium nitrate, ammonium nitrate, sodium nitrate, phosphoric acid, potassium dihydrogen phosphate, sulphuric acid, potassium sulphate, perchloric acid, ammonium perchlorate, and acetic acid all give solutions which yield no measurable excess of water or dinitrogen pentoxide in the vapour. There is some evidence for the dehydration of orthoboric acid by nitric acid, since the vapour contains an excess of water; acetic anhydride and acetyl nitrate yield vapours containing a marked excess of dinitrogen pentoxide. Since the data for water and the alkali-metal nitrates give straight lines (after suppression of the solvent dissociation) when the partial pressure of nitric acid p is plotted against the solute/solvent molecular ratio (m2/m1), provisional values for the numbers of particles (v) yielded by other solutes are derived by comparison with a graph of this kind. The same form of graph is also used to provide estimates of the extent of self-dissociation of nitric acid at 0°, 10°, and 20°, leading to results in fair agreement with those obtained by other methods. By continuing the vapour-pressure measurements to the limit of saturation, values are obtained for the solubilities of a number of substances in nitric acid.