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S. Mustafa ¹, M. Safdar ¹, Samad Yar Hussain ¹

Affiliations
1 National Centre for Excellence in Physical Chemistry, University of Peshawar, Peshawar, PK

Abstract

zn²⁺ ion adsorption from aqueous solution on α-Al(OH)₃ has been studied as a function of temperature. A simple method is described to evaluate the adsorption stoichiometry and apparent stability constants of the surface complex of the type [(AlO)_nM^2-n]. Thermodynamic parameters ΔG⁰, ΔH⁰ and ΔS⁰ for the process are also computed.

Keywords

Adsorption, Stability Constants, Thermodynamics.

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S. Mustafa ¹, M. Safdar ¹, Samad Yar Hussain ¹

Affiliations
1 National Centre of Excellence in Physical Chemistry, University of Peshawar, PK

Abstract

Adsorption of Cu²⁺, Zn²⁺, Co²⁺, and Ni²⁺ from aqueous solution on α-aluminium hydroxide is studied as a function of temperature, using the method of potentiometric titrations. Adsorption is found to be endothermic in nature and follows the order Cu²⁺ > Zn²⁺ > Co²⁺ > Ni²⁺ in the temperature rangc 20-50 °C. The adsorption stoichiometry and apparent stability constants of the surface complex of the type [(AIO)_n M^2-n]are also evaluated. In case of Cu²⁺ and Ni²⁺ the process is favoured by positive values of the ΔS⁰, while in case of Cu²⁺ and Zn²⁺ the process is favoured both by the negative values of ΔG⁰ and positive values of ΔS⁰.

Keywords

Adsorption, Stability Constants, Thermodynamic Parameters.

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