The surface tension of concentrated aqueous solutions of 1.1-electrolytes measured by means of Wilhelmy and laser light scattering methods

Surface tension measurements were made on concentrated (<4 moles/kg) aqueous solutions of the following 1.1-electrolytes: KF, KCl, KI, HCl, and HNO₃. Two different measurement techniques were used: the Wilhelmy slide method and a method based on the scattering of laser light by small amplitude liquid surface waves. The surface tension determined by the two methods agrees within ±0.5% and for each solution it is found to vary almost linearly with concentration. The shear viscosity was also measured for these solutions by means of the laser method and a standard flow viscosimeter. The measured values were found to agree within ±5%.