The disulphuric acid solvent system. Part II. Cryoscopic and conductimetric measurements on some organic and inorganic bases
Cryoscopic and conductimetric measurements on a number of weak organic bases have shown that they are more extensively ionized in disulphuric acid than in sulphuric acid or fluorosulphuric acid. It is concluded that disulphuric acid is a more acidic medium than either of these other solvents. It is shown how the cryoscopic data for any solute may be interpreted to give a value for ν, the total number of moles of all species except sulphuric acid, formed in solution by one mole of a solute, and also a value for the number of moles of sulphuric acid. The conductimetric data may be interpreted to give the number of moles of HS3O10– and H2SO4 formed by each mole of solute. The results of the conductimetric and cryoscopic measurements show that HClO4 behaves as a very weak base and that KCl and KF give quantitative formation of HSO3Cl and HSO3F respectively, both of which behave as nonelectrolytes. KlO3 forms lO2SO4H and KH2PO4 gives the P(OH)4+ ion. Nitric acid gives the nitronium ion, and triphenylmethanol the triphenylcarbonium ion. A number of carboxylic acids, are shown to be dehydrated to the corresponding acyl ion, e.g., CH3CO2H→CH3CO+.