surface tensions and thermodynamic parameters of surface formation of aqueous salt

Student:Saeed jaberzade

a b s t r a c t

1- Concentration and temperature dependence of the surface tension of chloride, bromide and iodide salts of potassium

2- estimation of surface excess concentration3- thermodynamic quantities of surface formation such as enthalpy and entropy were estimated

Previous works from this article

• 1- Onsager & Samaras(1934) • 2- Randles & Delahay (1963)• 3- Lu (2001)• 4- Matubayasi & Matsuo(1999)• 5- Johansson &Eriksson (1974)• 6- Ikeda & Aratono (1992)• 7- Literature(2007)

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Experiment

• aim of the study was to apply recently developed approach to aqueous solutions of chloride, bromide and iodide salts of potassium

• measurements of surface tension of aqueous solutions of chloride, bromide and iodide salts of potassium, as a function of concentration and temperature

• The surface tension was determined by the drop method using a stalagmometer

drop method

stalagmometer

The drop of a mass m gets released when its weight G=mg is equal or greater than the surface force at the end of tube.

• 1- drop-weight method

• 2- drop counting method

a) 20 water drops into the weighing bottleb) Determine the mass of 20 dropsc) Determine the surface tension d) Repeat steps

m = V × ρTotal mass of release water:

Mass of one drop:

Concentration dependence of surface tension of KBr solution at different temperatures

Concentration dependence of surface tension of KI solution at different temperatures

Concentration dependence of surface tension of KCl solution at different temperatures

Results and discussion

1-

2-

Temperature dependence of surface tension of KBr solution at different concentrations

Temperature dependence of surface tension of KI solution at different concentrations

Temperature dependence of surface tension of KCl solution at different concentrations

Results and discussion

Eötvös rule:

Substituting value of V:

Results and discussion

Temperature dependence of dγ/dC of KCl, KBr and KI salts solutions.

heat of hydration of the ions

The heats of hydration of Cl−, Br− and I− have been determined experimentally to be 354.1, 326.9 and 285.9 kJ mol−1

Concentration dependence of surface excess concentration of KI solutions at different temperatures.

Temperature dependence of surface excess concentration of KI solutions at different concentrations

(a) Concentration and (b) temperature dependence of enthalpy of KI solutions at different temperatures and concentrations

Concentration dependence of entropy of surface formation of KBr solution

References:1)Surface tensions and thermodynamic parameters of surface formation of aqueous salt solutions: III. Aqueous solution of KCl, KBr and KI Colloids and Surfaces A: Physicochemical and Engineering Aspects Khurshid Ali, Anwar-ul-Haq Ali Shaha, , ∗Salma Bilal, Azhar-ul-Haq Ali Shahb(2009)

4)Surface tension of strong electrolytes Y. Levin1 and J. E. Flores-Mena(2001)

2)The surface tension of liquids measured with the stalagmometer English version prepared by N. Kučerka, PhD.

3) Measurement of the dynamic surface tension by the drop weighing method Colloid & Polymer Sci. 253, 929-936 (1975)

5) Direct experimental validation of the Jones–Ray effectPoul B. Petersen, Justin C. Johnson, Kelly P. Knutsen, Richard J. Saykally Chemical Physics Letters 397 (2004) 46–50

Thanks for your attention