Water activity data representation of aqueous solutions at 25°C

Polynomial expressions have been fitted to the complete range of available water‐activity data for 396 electrolyte and non‐electrolyte aqueous binary systems. The standard deviation of regression rarely exceeded 0.001 and was less than 0.0002 in most cases. Such data representation is useful for the prediction of the water‐activity of mixed moderately concentrated aqueous solutions.