The density, viscosity, and surface tension of 0.5 M sodium carbonate + 0.5 M sodium bicarbonate buffer solutions in the presence of glycerin, glucose, or sucrose were measured at temperatures from 25 degrees C to 40 degrees C. The-concentration ranges were (0-187.2) g.dm(-3) for glycerin, (0-264) g.dm(-3) for glucose, and (0-204) g.dm(-3) for sucrose. The experimental values were correlated with the concentration of the organic component. The maximum deviations were always less than 0.5%.