Effect of pre-heating on the surface tension of NaCl solutions

الملخص EN

Surface tension of aqueous sodium chloride solutions has been measured in the concentration range 0M CNaCl 3M by the Du Nouy ring method.

The surface tension of the NaCl solutions increases linearly with increasing salt concentration in good agreement with reported results.

Without pre-heating- the NaCl solid sample to 520 oC- the surface tension displays a time dependent at a concentration of the 3 M.

With pre-heating- the sample at the mentioned temperature- the surface tension stays constant with time du to removal of impurities.

This simple experiment indicates the importance of heating in the measurement of surface tension of salt solutions.