Studies on metal hydroxy compounds. XII. Thermal analyses, decomposition kinetics, and infrared spectra of copper basic oxysalts

1970 ◽  
Vol 48 (22) ◽  
pp. 3510-3519 ◽  
Author(s):  
P. Ramamurthy ◽  
E. A. Secco
Keyword(s):  
Thermal Analyses ◽  
Three Dimensional ◽  
Decomposition Reaction ◽  
Sphere Model ◽  
First Order ◽  
Calorimetric Measurements ◽  
Infrared Spectral ◽  
Anionic Species ◽  
Hydroxy Compounds ◽  
Kinetics Of

The thermal analyses of copper basic oxysalts of the type Cu2(OH)2XOy, where X = S, C, Cl, Br, I, N, HC and y = 4, 3, or 2 reveal that decomposition occurs, in most cases, by dehydroxylation with concomitant disproportionation of the oxysalt. An outstanding exception to this pattern of decomposition is the basic sulfate. Calorimetric measurements along with related enthalpic values for the decomposition reaction are given.The kinetics of thermal decomposition of the compounds are classified into three main categories: (i) three-dimensional contracting sphere model, (ii) first-order rate, and (iii) nucleation controlled rate processes.The infrared spectral data of nine copper basic oxycompounds in the frequency region 4000–250 cm−1 are presented with their assignments. The fundamental infrared inactive modes of the anionic species SO42−, NO3−, etc. become active by the presence of the copper hydroxide ligand indicating a lowering of symmetry in the anion.

Studies on metal hydroxy compounds. XI. Thermal analyses, decomposition kinetics, and infrared spectra of cadmium and zinc halide derivatives

1970 ◽  
Vol 48 (17) ◽  
pp. 2656-2661 ◽  
Author(s):  
P. Ramamurthy ◽  
E. A. Secco
Keyword(s):  
Model Equation ◽  
Thermal Analyses ◽  
Decomposition Reaction ◽  
Decomposition Kinetics ◽  
Frequency Region ◽  
First Order ◽  
Calorimetric Measurements ◽  
Infrared Spectral ◽  
Hydroxy Compounds ◽  
Kinetics Of

The thermal analyses of Cd2(OH)3X type of basic halides reveal that the decomposition occurs via a two-step dehydroxylation pattern, yielding CdOHX as an intermediate product after the initial mode. These results suggest that Cd2(OH)3X is an addition compound of the hydroxide and the 1:1 hydroxy-halide, i.e. Cd(OH)2•CdOHX. Calorimetric measurements along with related enthalpy values for the decomposition reaction are given.The kinetics of thermal decomposition of the compounds are classified into two main groups: (i) two-dimensional contracting plate model equation and (ii) first-order rate law.The infrared spectral data of thirteen Cd and Zn basic halides in the frequency region 4000–250 cm−1 are presented with their assignments.

Studies on Metal Hydroxy Compounds. XIII. Thermal Analyses and Decomposition Kinetics of Hydroxystannates of Bivalent Metals

1971 ◽  
Vol 49 (17) ◽  
pp. 2813-2816 ◽  
Author(s):  
P. Ramamurthy ◽  
E. A. Secco
Keyword(s):  
Thermal Analyses ◽  
Decomposition Reaction ◽  
Decomposition Kinetics ◽  
Order Reaction ◽  
First Order ◽  
Calorimetric Measurements ◽  
Bivalent Metals ◽  
Hydroxy Compounds ◽  
Kinetics Of ◽  
Subsequent Decomposition

The thermal analyses of hexahydroxystannates of bivalent metals of the type Me[Sn(OH)6], where Me = Zn, Co, Cu, Ni, Mn, Ca, Mg, Cd, Sr, reveal that the primary mode of decomposition occurs by dehydroxylation and subsequent decomposition of the metastannate residue occurs in the Zn, Cu, Mn, Ca, and Mg compounds. Calorimetric measurements along with related enthalpic values for the decomposition reaction are given. The kinetics of thermal decomposition of all compounds studied, except the Cd and Mg analogues, follow first order reaction kinetics up to α ~ 0.9.

Studies on metal hydroxy compounds. X. Thermal analyses, decomposition kinetics, and infrared spectra of lead halide (Cl, Br, I) derivatives

1970 ◽  
Vol 48 (16) ◽  
pp. 2617-2622 ◽  
Author(s):  
P. Ramamurthy ◽  
E. A. Secco ◽  
M. Badri
Keyword(s):  
Infrared Spectra ◽  
Rate Equation ◽  
Thermal Analyses ◽  
Decomposition Reaction ◽  
Diffusion Type ◽  
Type Rate ◽  
Hydroxy Compounds ◽  
Kinetics Of ◽  
Lead Halide ◽  
Order Rate Equation

The thermal analyses, thermogravimetry (TG), and differential thermal analysis (DTA) of PbOHCl, PbOHBr, and PbOHI reveal that the initial mode of decomposition is via dehydroxylation. Calorimetric measurements along with related enthalpy values for the decomposition reaction are given.The infrared spectra of these compounds are interpreted in terms of folded bands of (PbOH+)n tied together by halide ions consistent with their crystal structures.The kinetics of thermal decomposition of lead hydroxyhalides follow a diffusion-type rate equation which is in contrast to the simple first-order rate equation observed for most Cd, Zn, and Cu compounds. These two distinct rates are interpreted in terms of mobile OH or H species in the dehydroxylation step.

Metal Halide Ammines. 1. Thermal Analyses, Calorimetry, and Infrared Spectra of Cadmium Halide (Cl, Br, I) Derivatives

1971 ◽  
Vol 49 (23) ◽  
pp. 3831-3835 ◽  
Author(s):  
K. C. Patil ◽  
E. A. Secco
Keyword(s):  
Spectral Data ◽  
Infrared Spectra ◽  
Thermal Analyses ◽  
Decomposition Reaction ◽  
Metal Halide ◽  
Calorimetric Measurements ◽  
Infrared Spectral

The thermal analyses of cadmium halide hexammines reveal that decomposition occurs by loss of ammonia via the diammine and the monoammine. Calorimetric measurements along with related enthalpic values for the intermediate stable stages of the decomposition reaction are given.The infrared spectral data of the diammines and monoammines are presented with their assignments.

Kinetics of Reactions of 8-Quinolinol and Acetate with Hydroxyaluminum Species in Aqueous Solutions. 1. Polynuclear Hydroxyaluminum Cations

1971 ◽  
Vol 49 (10) ◽  
pp. 1683-1687 ◽  
Author(s):  
R. C. Turner ◽  
Wan Sulaiman
Keyword(s):  
Acetic Acid ◽  
Rate Constant ◽  
Empirical Equation ◽  
Decomposition Reaction ◽  
Order Rate Constant ◽  
Acetate Concentration ◽  
First Order ◽  
Order Rate ◽  
Pseudo First Order ◽  
Kinetics Of

The effect of varying 8-quinolinol and acetate concentration on the rate of decomposition of poly-nuclear hydroxyaluminum cations was studied. It was found that the concentration of the undissociated 8-quinolinol and acetic acid molecules determined the magnitude of the first order rate constant for the decomposition of the polynuclear hydroxyaluminum cations, except when the acetate concentrations were relatively high. With high acetate concentrations, it appeared that polynuclear acetate species were involved in the reactions. An empirical equation was developed showing the effect of 8-quinolinol and acetic acid molecule concentrations on the pseudo first order rate constant for the decomposition reaction.

scholarly journals Photodegradation of levofloxacin in aqueous and organic solvents: A kinetic study

2013 ◽  
Vol 63 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Iqbal Ahmad ◽  
Raheela Bano ◽  
Muhammad Ali Sheraz ◽  
Sofia Ahmed ◽  
Tania Mirza ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Degradation Rate ◽  
Hplc Method ◽  
Ph Profile ◽  
Degree Of Ionization ◽  
First Order ◽  
First Order Kinetics ◽  
Anionic Species ◽  
Ph Range ◽  
Kinetics Of

The kinetics of photodegradation of levofloxacin in solution on UV irradiation in the pH range 2.0-12.0 has been studied using a HPLC method. Levofloxacin undergoes first-order kinetics in the initial stages of the reaction and the apparent first-order rate constants are of the order of 0.167 to 1.807×10-3 min-1. The rate-pH profile is represented by a curve indicating the presence of cationic, dipolar and anionic species during the reaction. The singly ionized form of the molecule is non-fluorescent and is less susceptible to photodegradation. The increase in the degradation rate in the pH range 5.0-9.0 may be due to greater reactivity of the ionized species existing in that range. The rate appears to vary with a change in the degree of ionization of the species present in a particular pH range and their susceptibility to photodegradation. Above pH 9, the decrease in the rate of photodegradation may be a result of deprotonation of the piperazinyl group. The levofloxacin molecule is more stable in the pH range around 7, which is then suitable for formulation purposes. The photodegradation of levofloxacin was found to be affected by the dielectric constant and viscosity of the medium

Metal Halide Ammines. II. Thermal Analyses, Calorimetry and Infrared Spectra of Fluoride Ammines and Hydrates of Bivalent Metals

1972 ◽  
Vol 50 (4) ◽  
pp. 567-573 ◽  
Author(s):  
K. C. Patil ◽  
E. A. Secco
Keyword(s):  
Spectral Data ◽  
Infrared Spectra ◽  
Thermal Analyses ◽  
Metal Halide ◽  
Metal Fluoride ◽  
Bivalent Metal ◽  
Calorimetric Measurements ◽  
Infrared Spectral ◽  
Bivalent Metals ◽  
Experimental Values

Thermal analyses of bivalent metal fluoride ammines reveal that decomposition occurs in two or more steps. Calorimetric measurements along with related enthalpic values of the various decomposition steps are given.The infrared spectral data of the ammines and hydrates are compared with theoretical and some experimental values already in the literature.

scholarly journals Studies on Metal Hydroxy Compounds. XIV. Thermal Analyses, Calorimetry, and Decomposition Kinetics of Heterocationic Hydroxy Chloride Compounds

1973 ◽  
Vol 51 (23) ◽  
pp. 3882-3888 ◽  
Author(s):  
Ah-Dong Leu ◽  
Palepu Ramamurthy ◽  
Etalo A. Secco
Keyword(s):  
Thermal Decomposition ◽  
Rate Equation ◽  
Thermal Analyses ◽  
General Pattern ◽  
Type Equation ◽  
First Order ◽  
Order Rate ◽  
Kinetics Of ◽  
Order Rate Equation ◽  
Initial Mode

Studies were carried out on two series of mixed metal hydroxy chloride compounds of the type xMe(OH)2•yMCl2 where Me = Cd, Cu and M = Mn, Co, Ni, Cu, Zn, Cd, Mg, or Ca.Thermal analyses for the Cd–M series reveal that the initial mode of decomposition involves a dehydroxylation step with a concomitant metathetical reaction between MCl2 and CdO. The compound CdCl2•2CdO is formed and decomposes at higher temperature leading to the eventual volatilization of CdCl2. The kinetics of thermal decomposition follow a simple first-order rate equation. The sole exception to this general pattern of behavior is the Cd–Zn compound.The initial mode of thermal decomposition of the Cu–M series compounds follows a parallel pattern described for the Cd–M series. The kinetic data for the Cu–M series are fitted into three groups: (i) phase boundary control embracing the contracting sphere and contracting plate model equations, (ii) A-E type equation with n = 2, and (iii) first-order rate equation.

Kinetics of the First Order Autocatalytic Decomposition Reaction of Nitrocellulose (13.86% N)

2010 ◽  
Vol 22 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Peng-Jiang Guo ◽  
Rong-Zu Hu ◽  
Bin-Ke Ning ◽  
Zheng-Quan Yang ◽  
Ji-Rong Song ◽  
...  
Keyword(s):  
Decomposition Reaction ◽  
Autocatalytic Decomposition ◽  
First Order ◽  
Kinetics Of

Kinetic of oxidation of methyl orange by vanadium(V) under conditions VO2+ and decavanadates coexist: Catalysis by Triton X-100 micellar medium

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Methyl Orange ◽  
Solution Ph ◽  
Vanadium Concentration ◽  
Limiting Behavior ◽  
First Order ◽  
First Order Kinetics ◽  
Ph Range ◽  
Kinetic Pattern ◽  
Triton X ◽  
Kinetics Of

The kinetics of oxidation of methyl orange by vanadium(V) {V(V)} has been investigated in the pH range 2.3-3.79. In this pH range V(V) exists both in the form of decavanadates and VO2+. The kinetic results are distinctly different from the results obtained for the same reaction in highly acidic solution (pH < 1) where V(V) exists only in the form of VO2+. The reaction obeys first order kinetics with respect to methyl orange but the rate has very little dependence on total vanadium concentration. The reaction is accelerated by H+ ion but the dependence of rate on [H+] is less than that corresponding to first order dependence. The equilibrium between decavanadates and VO2+ explains the different kinetic pattern observed in this pH range. The reaction is markedly accelerated by Triton X-100 micelles. The rate-[surfactant] profile shows a limiting behavior indicative of a unimolecular pathway in the micellar pseudophase.

Sign in / Sign up

Export Citation Format

Share Document