The true molecular weight of sulfonate soaps

The true mol wt of a sulfonate soap can be determined by osmometry if the soap is initially converted to its methyl ester. Conversion is ef‐fected by reactingvthe soap with (CH 3 ) 2 SO 4 under proper conditions. This method not only affords a simple and reliable means of measuring sulfonate mol wt, but also allows one to character‐ize a particular sample in terms of its disulf onate and sulfone content.