COORDINATION COMPOUNDS OF COPPER, COBALT AND NICKEL FORMATES WITH FORMAMIDE AND CARBAMIDE

The synthesis of mixed ligand coordination compounds of copper, cobalt and nickel formates with formamide and urea in an aqueous solution was carried out. The metal content in the complexes was determined by complexometric titration. Using IR spectroscopy, it was proved that the coordination of formamide and urea with the complexing atom is carried out through the oxygen atom of the carbonyl group. The absorption spectrum of coordinated water is also present in the IR spectrum. The nature of the change in the frequency of stretching vibrations of the –OH group in the composition of water indicates its location in the nearest coordination sphere of the central atom. Derivatographic analysis investigated the thermal behavior of the obtained compounds. Based on the nature of the heating curves, sequential cleavage of water and ligands is shown and a molecular formula for synthesized compounds is proposed. The equation of the synthesis reaction of these coordination compounds is also given.

An investigation on the synthesis of nickel aluminate

Purpose The purpose of this paper is to study the process of coprecipitation of polyhydroxocomplexes of nickel and aluminum from solutions of nickel (Ni) (II) sulfate and aluminum (Al) (III) sulfate with caustic soda and to study the conversion process to nickel aluminate and to check its properties. Design/methodology/approach For the thermodynamic analysis of the precipitation process, the software package MEDUSA was used. The dependences of the electrical conductivity, pH and residual concentrations as functions of the OH/Me ratio were obtained. Using X-ray phase analysis, spectroscopic analysis and derivatographic analysis, the properties of the products obtained were studied. The effects of OH/Me ratio and molar ratio cation of reagents on the physicochemical properties of the products were analyzed. Findings The paper deals with the results of theoretical and experimental research on the synthesis pigments of blue and green colors based on Ni-Al spinel. The influence of the molar ratio cation content on optical and color characterise of pigments were studied. Originality/value The original complex method of studying the processes of co-precipitation of cations in the form of hydroxides is proposed. pH precipitation of aluminum hydroxide and nickel are different. It is interesting to study their co-precipitation. The resulting single-phase product is a precursor of nickel aluminate over a wide range of cation ratios. The dependences of the electrical conductivity, pH and residual concentrations as functions of the OH/Me ratio were obtained.

Identification of kinetic triplets by results of derivatographic analysis

The method for identification of the triplet of kinetic parameters of a heterogeneous reaction using the data of the derivatographic analysis is proposed. This method is characterized by high accuracy and relative simplicity and it can be effectively realized using MS Excel software.

Determination of Total and Free Water in Triple Superphosphate Fertilizers by Using Thermal Analysis

Thermal analysis methods were used to study dehydration of triple superphosphate. A redrying procedure followed by Q-derivatographic analysis (under quasiisobaric and quasiisothermal conditions) as well as differential scanning calorimetry (DSC) was applied. Attempts were made to establish the correct drying-oven temperature for determination of water content, i.e., the temperature at which free or total water is removed from the fertilizer. Thermal decomposition of monocalcium orthophosphate monohydrate, the major component of triple superphosphate, was studied and a model was advanced for the reactions that occur during decomposition of this salt. The free water was completely released when superphosphate was heated at a constant temperature of 85°C. The total water was entirely released at 160°C. At 150°C, the process of removing the water of crystallization from the orthophosphate was disturbed by other concomitant dehydration processes which result in irreversible decomposition of this salt. The results obtained indicate that the thermal methods of analysis used are complementary.