Kinetic Study of the Catalyzed Decomposition of Hydrogen Peroxide and Measurement of Activation Energy

Abstract

The purpose of this work is to study the decomposition of hydrogen peroxide into water and oxygen. Aqueous homogenous system and pH 6.00 were used. The rate constant was measured in the presence and absence of the catalyst. Crystal Violet was used as oxidation indicator. Catalysts were used to activate the decomposition of the hydrogen peroxide by using ammonium iron(II) sulphate, iron(III) sulphate, cobalt chloride, Manganese sulphate, Manganes (IV) oxide or/and Nickel(II) sulphate. It has been found that the order of catalytic activities were ferrous> ferric> Nickel, (II), copper (II), manganese (II)> cobalt (II), manganese (IV). UV-Visible spectrophotometer was used to follow up the concentration of oxidation indicator, and as a function of time the resulting reaction was pseudo first order reaction. The activation energy was measured using two different methods. A- Kinetic theory, using iodometric titration. Rate constant was determined at two different temperatures 17.25 and 23 C̊ and activation energy was found to be 73.908 KJ Mole- . B- Nudge elastic band theory within the Quantum Espresso computational package was used to calculate the same activation energy for the reaction. The calculation is carried out and the activation energy was found to be 88 KJ Mole- .