The mean activity coefficients of sodium salts of 1-amino-4-alkylaminoanthraquinone-2- sulfonic acid (alk= Me (MAS), Et, n-Pr, or n-Bu (n-BAS)) in aqueous solutions ranging in concentration from 10− 3 to 10− 2 mol kg− 1 have been determined by means of isopiestic measurements at 50 and 60° C respectively. It has been found that the mean activity coefficients of these dyes are much smaller than unity, the coefficients of MAS being the ...
