Sulphonation in aqueous sulphuric acid

The first kinetic study appears to have been that of Martinsen148, who found that the sulphonation of 4-nitrotoluene in 99.4-100.54 wt. % sulphuric acid was first-order in aromatic and apparently zeroth-order in sulphur trioxide, the rate being very susceptible to the water concentration. By contrast, Ioffe149 considered the reaction to be first-order in both aromatic and sulphur trioxide, but the experimental data of both workers was inconclusive. The first-order dependence upon aromatic concentration was confirmed by Pinnow150, who determined the equilibrium concentrations of quinol and quinolsulphonic acid after reacting mixtures of these with 40-70 wt. % sulphuric acid at temperatures between 50 and 100 °C the first-order rate coefficients for sulphonation and desulphonation are given in Tables 34 and 35. The logarithms of the rate coefficients for sulphonation 

RATE COEFFICIENTS FOR SULPHONATION(s) AND DESULPHONATION (d) OF QUINOL AND QUINOLSULPHONIC ACID, RESPECTIVELY, AT 100 °C150 

H2SOi (Wt. %) /05MS) 10ski(D) h2so (Wt. %) lO kiiS) 10sk2(D) 

RATE COEFFICIENTS AT AN UNKNOWN TEMPERATURE AND ACTIVATION ENEROIES FOR REACTION OF H2S04 WITH ANTHRAQUINONE151 

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