0731. Solving a chemistry problem

4. Calculate the surface tension of an aqueous solution of butanol (C4H9OH) with a concentration of 0.1 mol/dm3 at 20 C, if the surface tension of a solution of propanol (C3H7OH) of the same concentration at the same temperature is 65.5 mJ/m2. The coefficient of the Duclos-Traube rule is 3. The surface tension of water at this temperature is 72.75 mJ/m2.