Sulfuric Acid Medium Research Articles

Influence of FeCO3 and FeSO4 Layers on Corrosion in Sulfuric Acid Medium of Eutetoid Steels

Influence of FeCO3 and FeSO4 Layers on Corrosion in Sulfuric Acid Medium of Eutetoid Steels

A MIXTURE OF ACACIA BARK EXTRACT (Acacia mangium Willd) AND POTASSIUM IODIDE AS A CORROSION INHIBITOR IN SULFURIC ACID SOLUTION

Corrosion is a decrease in the quality of a metal material caused by a reaction with the environment. Corrosion cannot be eliminated, but corrosion can be slowed down in several ways by adding corrosion inhibitors and synergistic effects. Acacia bark extract (Acacia mangium Willd) with the addition of 0.02 M KI has the potential as a corrosion inhibitor for steel because it contains secondary metabolites, so it can provide a synergistic effect and increase the value of inhibition efficiency on steel. This research aimed to analyze the effect of a mixture of acacia bark extracts (Acacia mangium Willd) with the addition of KI on inhibition efficiency corrosion of mild steel in sulfuric acid media. The method used in this study is the method of weight loss, adsorption isotherms, and thermodynamic parameters, which were carried out by varying the concentration of acacia bark extract and the immersion temperature of the steel. To strengthen the research results, characterization was carried out using FTIR and SEM. The results showed that the corrosion rate of mild steel immersed in 0.75 M H2SO4 corrosive medium with the addition of 0.02 M KI increased with increasing immersion temperature. These results are reinforced by the results of FTIR and SEM analysis which show that there is an interaction between mild steel and acacia bark extract (Acacia mangium Willd) and KI 0.02 M. Based on the thermodynamic parameters, the resulting values of ∆Hads, ∆Gads, and ∆Sads show that the adsorption process of acacia bark extract (Acacia mangium Willd) in corrosive medium H2SO4 0.75 M with the addition of 0.02 M KI took place spontaneously, showing the type of physical adsorption, adsorbed stable, the adsorption process was exothermic and the degree of irregularity in the adsorption process. The inhibition efficiency of acacia bark extract (Acacia mangium Willd) with the addition of 0.02 M KI was highest at 60 °C with an extract concentration of 2.5 g/L of 81%. The higher the immersion temperature, the greater the resulting synergistic effect

Novel N-heterocyclic Schiff base based on Isatin derivative as a sustainable, eco-friendly, and highly efficiency corrosion inhibitor for carbon steel in sulfuric acid medium: Electrochemical and Computational investigation

The present study aimed to synthesize and investigate the inhibitory effects of two novel Schiff bases namely: (Z)− 1-(5-nitro-2-oxoindolin-3-ylidene) semicarbazide (NOSC) and Z)− 1-(5-nitro-2-oxoindolin-3-ylidene) thiosemicarbazide (NOTSC) for carbon steel (CS) corrosion in 0.5 M H2SO4 medium. Through chemical and electrochemical investigations, the efficiency of NOSC and NOTSC's corrosion inhibition was ascertained experimentally at 298 K. It is noteworthy that the inhibitory efficacy of NOTSC and NOSC reached 93.4% and 91.6%, respectively, at a concentration of 10−3 M. Studies using potentiodynamic polarization revealed that NOTSC and NOSC functioned as mixed-type inhibitors. A depressed capacitive loop with varying concentrations is the primary way that the Nyquist plot of impedance is represented. The transportation of corrosive ions to the metal substrate is impeded by the adsorption of both NOSC and NOTSC, as determined by the Langmuir isotherm. Apart from the chemical and electrochemical investigations, additional insights were gained into the inhibitory mechanism by the application of density functional theory (DFT), molecular dynamics simulation (MDS), and an understanding of the molecular structure of NOTSC and NOSC. A robust correlation was discovered between the theoretical and experimental results through the application of DFT/MDS computational study.

ELECTROCHMEICAL SYNTHESIS OF TUNGSTEN OXIDE IN CHLORIDE SOLUTIONS FOR ENVIRONMENTAL PHOTOCATALYSIS

The electrochemical behavior of tungsten in chloride electrolytes with various cationic compositions (Na+, K+, Li+, NH4+) under pulse alternating current has been studied. The decisive influence of the nature of the electrolyte on the phase composition of the resulting dispersed products is shown. The use of NH4Cl ensures the formation of pure crystalline WO3 with a particle size of 30–35 nm. The photoelectrochemical activity of the synthesized WO3 in a sulfuric acid medium under simulated solar radiation has been studied. The addition of glycerol to H2SO4 causes a cathodic shift in the oxidation onset potential by 0.25 V and a threefold increase in the maximum photocurrent density. The possibility of using a WO3/FTO photoanode as part of a flow-through photocatalytic fuel cell (fuel - glycerol, air-breathing Pt/C cathode), characterized by excellent stability in an acidic environment and the maximum power density of 64.0 μW cm-2 is shown.

Electrochemical and DFT studies of Terminalia bellerica fruit extract as an eco-friendly inhibitor for the corrosion of steel

It is well known that metal corrosion causes serious economy losses worldwide. One of the most effective ways to prevent corrosion is the continuous development of high-efficient and environment-friendly corrosion inhibitors. Among the widely used organic and inorganic corrosion inhibitors, plant extracts are top candidates due to their nontoxic nature. The present study reports a novel application of the methanolic extract of Terminalia bellerica fruits as an environment friendly corrosion inhibitor for steel in sulphuric acid medium. The phytochemicals of the extract, namely Ellagic, Gallic, and Malic acids, play a key role of the anti-corrosive behavior of the extract. The corrosion prevention activity was studied on the steel in 1 M H2SO4 using a variety of approaches including weight loss analysis (WL), scanning electron microscope (SEM), electrochemical impedance spectroscopy (EIS), density functional theory (DFT), natural bond orbital analysis (NBO), Fukui function and Monte Carlo simulations (MC). In 1 M H2SO4 solution, the maximum electrochemical inhibition efficiency of 91.79% was observed at 4000 mg/L concentration of the extract. The NBO analysis showed that the charge density of the double bonds and the oxygen atoms of carbonyl and hydroxyl groups of the phytochemicals lies on the top of the natural bond orbitals which promotes the anticorrosive properties of the investigated inhibitors. The surface coverage of steel was validated by SEM measurements. According to DFT studies, numerous nucleophilic regions were present in the active phytochemical constituents of the inhibitor, demonstrating their favorable nucleophilicity. The computed electronic structure of the phytochemicals revealed band gaps of 4.813, 5.444, and 7.562 eV for Ellagic, Gallic, and Malic acids respectively suggesting effective metal-inhibitor interactions. A good correlation between experimental and theoretical findings was addressed.

A Synergistic Extraction for the Separation of Scandium with Cyanex572 and Cyanex923

AbstractThis paper investigates the synergistic extraction performance of Scandium using a mixture of Cyanex572 and Cyanex923 in sulfuric acid medium. The results show that the best synergistic effect is achieved when the pH value of the aqueous phase is 2 and the mole fraction of Cyanex572 is 0.5, with a synergy coefficient value R of 4.78. In addition, the extraction mechanism of this synergistic system is discussed, and the extracted complex is determined to be [Sc(SO4)0.5(HL2)2B2] by slope analysis. The loaded Scandium can be stripped within two times by 2 mol/L sulfuric acid to obtain a stripping efficiency of 99.4 %. Finally, this synergistic system was applied to extract Scandium, demonstrating the potential application in separation of Scandium from the leachate of laterite nickel ore.

Corrosion mitigation of peanut shell extract as a novel effective corrosion inhibitor for carbon steel in sulfuric acid medium

The extract of peanut shell extract (PSE) is firstly utilized as a novel eco-friendly corrosion inhibitor for the mitigation of corrosion on carbon steel in 0.5 M sulfuric acid medium. The corrosion inhibition performance and adsorption properties of PSE were researched via weight loss, electrochemical measurements and surface characterization analysis. It is demonstrated that the PSE acts as a mixed type inhibitor with a superb inhibition ability of 95 % with the addition of 300 mg/L PSE. The adsorption of the active ingredients in PSE on steel surface contributes to effective corrosion inhibition. The outstanding inhibition efficiency and straightforward extraction method with environment-friendly solvent convincingly demonstrate that the PSE possesses promising application prospects to be a novel eco-friendly corrosion inhibitor in industrial corrosion mitigation.

Kinetics, Mechanism, and Reactivity of the Cerium(IV)-Oxalatereaction in a Sulphate Medium

This work presents an approach for studying the kinetics, mechanism, and reactivity of intermediates in a wide class of the redox reactions for which the rate-limiting step is the redox-decomposition of an intermediate complex. This approach is applied to investigate the oxalic acid (H2Ox) oxidation by cerium(IV) in sulfuric acid medium, which is an integral part of the cerium-catalyzed oscillatory Belousov–Zhabotinsky (BZ) reaction. Using experimental, mathematical and computational techniques commonly used to study metal complexes in a stable oxidation state (OS), kinetically generalized by the authors for studying variable-valence metal complexes, the characteristics of intermediate complexes of the cerium(IV)-oxalate reaction were studied, the general rate law was derived on the basis of a set of equations describing the rapid establishment of preequilibria in the system and the subsequent nonequilibrium process. A quantitative reaction model is proposed that includes two parallel reaction pathways, for which two different intermediate cerium(IV)-oxalate complexes with close reactivity have been identified and characterized that may be due to the similarity in the structure of their inner coordination spheres and an inner sphere mechanism of electron transfer in the complexes. Based on the developed model, the distribution diagram was also constructed for the computed fractions of all the detectable cerium(IV) species under conditions of the BZ reaction, which testify to the necessity to take into account under these conditions the formation of intermediate complexes CeOHOx (n = 1, 2) during oxidation of oxalic acid. The main difference of the proposed model of the cerium(IV)-oxalate reaction as part of the BZ-reaction from the previous models is the explicit accounting of the formation of intermediate cerium(IV) complexes with anions of oxalic acid and sulfate background.

Evaluating (p-Semidine-Guanidine-Formaldehyde) terpolymer resin efficiency as anti-corrosive agent for mild steel in 1 M H2SO4: An experimental and computational approach

Corrosion is a critical concern in various industrial applications, especially in acidic environments. In this study, for the first time, we investigate the efficient anti-corrosive effect of (p-Semidine-Guanidine-Formaldehyde) terpolymer resin on mild steel in a corrosive sulfuric acid (H2SO4) medium. The research employs a comprehensive approach, combining experimental and computational methods to gain deeper insights into the corrosion inhibition mechanism. Electrochemical and gravimetric measurements are performed to determine when the inhibitor is incorporated andor not, mild steel corrodes at similar rates. The inhibition efficiency (%) is calculated based on the obtained data, revealing the effectiveness of the terpolymer resin showing an inhibitory efficacy of 93.70 % at an ideal concentration of 1 × 10−3 M as a corrosion inhibitor. Moreover, the adsorption behavior of the inhibitor on the mild steel surface is examined, and a Langmuir adsorption isotherm model is applied to explain the adsorption process. The computational simulations including HOMO and LUMO analyses shed light on the electronic properties and chemical structure of the (p-Semidine-Guanidine-Formaldehyde) terpolymer resin, elucidating its anti-corrosive mechanism. These findings hold significant implications for designing effective and environmentally friendly corrosion inhibitors for various industrial applications, leading to improved material durability and safety.

Investigation of corrosion inhibition performance of expired fluconazole drug on mild steel in 0.5M H2SO4 medium

Fluconazole is a pharmaceutical drugused for the treatment of fungal infections.The disposal of the expired Fluconazoledrug threatens the environment, but still, it contains active components. The potentiality of the active components of the expired Fluconazole drug was utilized to guard the mild steel corrosion in0.5 M sulphuric acid medium. Electrochemical and mass loss studies were used to evaluate the drug's capacity to protect mild steel surfaces against corrosion. The outcomes of the studies demonstrate that Fluconazole effectively inhibits the corrosion of mild steel in sulphuric acid solution at various temperatures.The maximum inhibition efficiency obtained by the mass loss method was 93.75% at 110 ppm drug concentration. Fluconazole molecules have been determined to follow the Langmuir adsorption isotherm model. The SEM images visualized that, in the presence of drug molecules th mild steel surface was least affected by the acid solution compared to the blank solution. The water contact angle data revealed that the adsorption of Fluconazole molecules builds mild steel surfaces that are more hydrophobic in nature. The inhibitor molecules retard both anodic and cathodic reactions in an acid medium and act as a mixed-type inhibitor. DFT calculations and Molecular dynamics simulations further elucidated the chemical interactions between Fluconazole and the mild steel surface.

Usage of Grewia bicolor Juss leaves extract as green corrosion inhibitor for Steel XC40 in sulfuric acid medium

Usage of Grewia bicolor Juss leaves extract as green corrosion inhibitor for Steel XC40 in sulfuric acid medium

Surface morphology and corrosion behavior of pure aluminum and its alloys in aqueous sulfuric acid medium

AbstractAluminum and aluminum alloys are light materials with some of the preferences such as lightweight, high specific strength, good elasticity, and good workability that play an important role in today's modern and industrial world. The economic loss and environmental and safety problems are also the most concerning aspects of these materials. As a result, numerous studies are performed by the researchers to improve the overall environment throughout the materials world. That is why, in this study, the surface morphology and corrosion behavior of pure aluminum and its alloys, such as 7S10 and 7003H, were investigated in aqueous sulfuric acid medium through immersion process at different temperatures. Open‐circuit potential and potentiodynamic polarization techniques were used to evaluate the resistance to corrosion of pure aluminum and its alloys 7S10 and 7003H. The current density increased with increasing temperature in the case of the alloys, and pure aluminum showed the highest corrosion resistance properties. The surface roughness measurement was performed using atomic force microscope to find out the amount of roughness of the used materials before and after the immersion process. Surface roughness was higher on the alloys than in pure Al, which indicates that less corrosion was formed in pure Al than in the alloys. The surface morphology analysis was also carried out using scanning electron microscopic data. The results revealed that the alloy 7003H undergoes more corrosion than pure aluminum and 7S10 in sulfuric acid medium, which clearly indicates that pure aluminum has higher corrosion resistance than the alloys 7S10 and 7003H. The corrosion rate of the test materials decreased with increasing immersion time.

Selective extraction of Ti(IV) from acidic sulfate media by phosphonium-based ionic liquids and stripping with sulfuric acid

The Ti(IV) liquid-liquid extraction from acidic sulfate media has been investigated by the ionic liquids trihexyl(tetradecyl)phosphonium chloride [P66614+][Cl−] and trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate [P66614+][BTMPP−], diluted in 5% (v/v) 1-decanol/kerosene. The Room Temperature Ionic Liquids (RTIL) showed fast extraction kinetics reaching equilibration after 2 min, requiring a 450 rpm stirring rate. For [P66614+][Cl−] at 0.01 mol L−1, the maximum extraction efficiency was 30% from H2SO4 solution of 11 mol L−1. The IL [P66614+][BTMPP−] shows better Ti(IV) extraction than [P66614+][Cl−], and two maximum extraction conditions were observed at 0.1 and 7.3 mol L−1 H2SO4 due to the dual mechanism; both cationic and anionic exchange reactions, reaching 60% and 49% extraction efficiency, respectively.The increase in [P66614+][BTMPP−] concentration to 0.06 mol L−1, increases the extraction yield to 95.9%. The Fourier transform infrared FTIR characterization confirmed the presence of Ti(IV) in the organic phases, and the modification in the phosphonium bonds was correlated to the role of the ionic liquids in the Ti(IV) extraction. The organic phase containing 0.02 mol L−1 [P66614+][BTMPP−] can be loaded with 0.197 g/L of Ti(IV) from 7.3 mol L−1 H2SO4 media. In contrast, at 0.1 mol L−1 H2SO4, an increase in the Ti(IV) concentration promotes the polymerization in the form Ti-O-Ti-O-Ti inhibiting the extraction efficiency. The H2SO4 solution at 2 mol L−1 was the best stripping agent to achieve a high Ti(IV) recovery of 97%. The organic phase was reused for four cycles, and the extraction and stripping efficiencies remained unchanged after the third cycle. The selective separation of Ti(IV) from a mixture containing Fe(III) was reached with a separation factor of 78.4, with a 2.51% Fe(III) extraction and containing only 0.25 mg L−1 of Fe(III) in the stripping phase. The proposed system avoids the main problems associated with Ti(IV) recovery from acidic sulfate media.

Lycium barbarum leaf extract as biodegradable corrosion inhibitor for copper in sulfuric acid medium

Corrosion protection of metals is a significant research field that requires the development of safe, non-toxic, cost-effective, and environmentally friendly high-performance corrosion inhibitors. This study employed a water-based extraction method to obtain Lycium barbarum leaf extract (LBL) and utilized a series of experimental and theoretical approaches to evaluate its corrosion protection efficacy on copper in 0.5 mol/L sulfuric acid environments. The electrochemical tests unequivocally demonstrated the outstanding corrosion inhibition ability of LBL, with corrosion inhibition efficiencies of 92.9%, 92.8%, and 94.1% observed at a concentration of 400 mg/L and temperatures of 298 K, 303 K, and 308 K, respectively. Advanced techniques such as Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were employed to comprehensively characterize the chemical composition and functional groups of LBL and the surface of copper samples immersed in the LBL. Furthermore, scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to observe and analyze the morphology of acid-corroded copper surfaces and those protected by LBL. As a supplement to the experimental findings, quantum chemical calculations and molecular dynamics simulations were employed to explore the theoretical aspects of the active constituents in LBL and simulate their adsorption behavior.

Insight into the corrosion inhibition performance of Jasmine flower extract on copper in sulfuric acid medium using experimental and theoretical calculation methods

BackgroundCopper is widely used in all areas of society, but it is easy to be corroded in corrosive media, which causes certain economic losses. Among many anti-corrosion methods, adding corrosion inhibitors is an efficient, convenient and common method. However, there are some shortcomings in traditional corrosion inhibitors, so it is urgent to develop an efficient corrosion inhibitor with no toxicity and low cost as well as no harm to the environment. MethodsThe corrosion performance of Jasmine flower extract (JFE) for copper in 0.5 mol/L sulfuric acid medium was studied by electrochemical test, and the microstructure and chemical composition of copper surface were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and atomic force microscope (AFM). The interaction mechanism between corrosion inhibitor molecules and copper was analyzed based on theoretical calculation. Significant findingsThe results show that JFE is an efficient and environment-friendly corrosion inhibitor. In a certain temperature range (298 ∼ 308 K), when the concentration of JFE is 500 mg/L, the corrosion inhibition efficiency (η) is not less than 94.0%. According to Langmuir adsorption model, the JFE adsorbs on the copper surface as a mixed type of inhibitor.

Insight into the anti-corrosion mechanism of Chinese mahonia leaves as a green and bio-degradable against copper corrosion in sulfuric acid medium

BackgroundMetal corrosion not only leads to significant economic losses for the country but also poses a considerable threat to human safety. The majority of corrosion inhibitors available in the market today fail to meet the demand of industrial production for green and sustainable development. Therefore, it is the pursuit of numerous researchers to find efficient, eco-friendly and low-cost methods for metal protection. MethodsIn this work, the information on the main components in extracts of Chinese mahonia leave (MLE) was determined by liquid chromatography-mass spectrometry (LC-MS). The functional groups of MLE were investigated using Fourier transform infrared spectroscopy (ART-FTIR). X-ray electron spectroscopy (XPS) was selected to detect bonding information between MLE and the surface of copper. The mechanism of the anti-corrosion in the Cu/H2SO4 system has been explored by theoretical calculation and electrochemical measurement. Significant findingsThe electrochemical results showed that MLE could prevent corrosion of copper in the H2SO4 system, and the inhibition efficiency (IE) was 91% at 300 mg/L, MLE predominantly forms a protective film on the copper surface by employing both weak interactions (electrostatic adsorption) and strong interactions (chemical coordination). These interactions effectively isolate the copper substrate from the corrosive medium, resulting in a reduction in the corrosion rate. Combining molecular dynamics simulations with theoretical calculations, we have further confirmed that the N, O, and other heteroatoms in MLE molecules play a crucial role in their corrosion inhibition performance.

Oxidative Capacity of Oxygen Nanobubbles and Their Mechanism for the Catalytic Oxidation of Ferrous Ions with Copper as a Catalyst in Sulfuric Acid Medium.

Nanobubble (NB) technology has demonstrated the potential to enhance or substitute for current treatment processes in various areas. However, research employing it as a novel advanced oxidation process has thus far been relatively limited. Herein, we focused on the oxidative capacity of oxygen NBs and investigated the feasibility of utilizing their enhanced oxidation of ferrous ions (Fe2+) in a sulfuric acid medium when using copper as a catalyst and their effect mechanism. It was demonstrated that oxygen NBs could collapse to produce hydroxyl radicals (·OH) in the absence of dynamic stimuli using electron spin resonance spectroscopy, and methylene blue was used as a molecular probe for ·OH to illustrate that NB stability, determined by their properties, is the critical factor affecting ·OH release. In subsequent Fe2+ oxidation experiments, it was discovered that both strong acidity and copper ions (Cu2+) contribute to accelerating the collapse of NBs to produce ·OH. While ·OH derived from the collapse of NBs acts on Fe2+, the molecular oxygen generated homologously with ·OH will further activate the catalytic oxidation of Fe2+ by interacting with Cu2+. With the synergistic effect of the above two oxidation-driven mechanisms, the oxidation rate of Fe2+ can be significantly increased up to 88% due to the exceptional properties of oxygen NBs, which facilitate the formation of an atmosphere with persistent oxygen supersaturation and the generation of oxidation radicals. This study provides significant insight into applying NBs as a prospective technology for enhanced oxidation processes.

Investigating the Inhibitory Properties of Cupressus sempervirens Extract against Copper Corrosion in 0.5 M H2SO4: Combining Quantum (Density Functional Theory Calculation-Monte Carlo Simulation) and Electrochemical-Surface Studies.

The study investigates the potential of Cupressus sempervirens (EO) as a sustainable and eco-friendly inhibitor of copper corrosion in a 0.5 M sulfuric acid medium. The electrochemical impedance spectroscopy analysis shows that the effectiveness of corrosion inhibition rises with increasing inhibitor concentrations, reaching 94% with the application of 2 g/L of EO, and potentiodynamic polarization (PDP) studies reveal that EO functions as a mixed-type corrosion inhibitor. In addition, the Langmuir adsorption isotherm is an effective descriptor of its adsorption. Scanning electron microscopy/energy-dispersive X-ray spectroscopy, atomic force microscopy surface examination, and contact angle measurement indicate that EO may form a barrier layer on the metal surface. Density functional theory calculations, Monte Carlo simulation models, and the radial distribution function were also used to provide a more detailed understanding of the corrosion protection mechanism. Overall, the findings suggest that Cupressus sempervirens (EO) has the potential to serve as an effective and sustainable corrosion inhibitor for copper in a sulfuric acid medium, contributing to the development of green corrosion inhibitors for environmentally friendly industrial processes.

Investigation Effect of 4-Aminophenol as a Corrosion Inhibitor for Mild Steel in Sulfuric Acid Medium

A high number of organic materials have been studied as inhibitors for corrosion in different conditions. In this paper, the effect of organic chemical (4-Aminophenol) as an inhibitor for mild steel metal corrosion was investigated in presence of sulfuric acid at different temperatures. The study was carried out using three known methods in testing corrosion process, methods of weight loss, thermometric, and polarization. The obtained results showed that when the inhibitor concentration increases, the corrosion rate decreases, and hence, the inhibition efficiency increases. Moreover, when the surface coverage at a temperature of 313 °C with organic inhibitor increases, the corrosion rate decreases as noticed in the weight loss method. For the thermometer method, the inhibitor was examined by temperature. The inhibition efficiency increases, as well as in the anodic and cathodic polarization method, where it is observed that the anodic and cathodic curves are present to measure the corrosion current and corrosion potential. As the higher the concentration of the inhibitor, the lower the current and the corrosion voltage. The reason for the effectiveness of this inhibitor is the presence of amine and phenol organic molecules in its composition, which can form a film on the metal surface and prevent corrosion from taking place.

Spectrophotometric Study of Kinetics of Redox Reaction between Caffeine and Permanganate Ion in Aqueous Acidic Medium

The kinetics of redox reaction between caffeine (hereafter referred to as CAF) and permanganate ion [MnO4-] has been studied spectrophotometrically in aqueous sulfuric acid medium. One mole of CAF was oxidized by one mole of [MnO4-].The reaction showed first-order kinetics with respect to both [CAF] and [MnO4-]. The investigation was carried out under pseudo-first order condition atI= 0.5 mol dm–3, (Na2SO4), T = 24± 0.1℃ and [H+] = 1.0 × 10–1mol dm-3. The reaction obeys the rate law: -d[MnO4-]/dt = (a+b [H+]) [CAF ] [MnO4-]. The reaction was retarded by increased in ionic strength of the reaction medium. The rate of the reaction showed dependence on acid (in the range used).Added anions and cations were observed to catalyze the reaction rate. Spectroscopic investigation and kinetic study did not suggest intermediate complex formation. An outer–sphere mechanism is proposed for the reaction.