On the reaction between molten lithium perchlorate and chromium(III) oxide
TL;DR: In this paper, the reaction at 300°C between molten lithium perchlorate and chromium(III) oxide gave lithium dichromate, and a reaction mechanism was proposed.
Abstract: The reaction at 300°C between molten lithium perchlorate and chromium(III) oxide gave lithium dichromate. When lithium perchlorate and chromium(III) oxide were in the formula weight ratio of 2:1 respectively, the chromium was oxidized completely into the hexavalent oxidation state, and only a negligible chloride percentage of 0·1 remained in the resulting lithium dichromate.
Different formula weight ratios were taken for the reaction at 300°C. In the runs where the formula weight ratios of the perchlorate and oxide were lower than 2:1, the amount of chromium oxidized was higher than expected by the proposed route, and an explanation is given. Reactions with 51Cr2O3 showed that a very small amount of chromium volatilized.
Results obtained from experiments both in vacuum and air were in very good agreement. A reaction mechanism is proposed.
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TL;DR: In this article, thermal decomposition studies of intimate mixtures of different molar ratios of potassium nitrate and chromium(III) oxide were made by employing thermogravimetry differential thermal analysis, chemical analysis, infrared spectral measurements and X-ray powder diffraction patterns.
Abstract: Thermal decomposition studies of intimate mixtures of different molar ratios of potassium nitrate and chromium(III) oxide were made by employing thermogravimetry differential thermal analysis, chemical analysis, infrared spectral measurements and X-ray powder diffraction patterns. Potassium nitrate in the presence of chromium(III) oxide starts decomposing around 350°C which is much below the decomposition temperature of pure potassium nitrate. Chromium(III) is completely oxidized into its hexavalent state when the mole ratio of KNO3 to Cr2O3 is greater than three.
11 citations
TL;DR: In this article, the thermal decomposition of ammonium perchlorate in the presence of potassium chloride and chromium (III) oxide was investigated using K36 Cl and51 Cr2 O3 to elucidate the reaction mechanism.
Abstract: The thermal decomposition of ammonium perchlorate in the presence of potassium chloride and chromium (III) oxide was investigated using K36 Cl and51 Cr2 O3 to elucidate the reaction mechanism. Two simultaneous routes are suggested for the decomposition. It was found that double decomposition in vacuo between potassium chloride and ammonium perchlorate does not result in the formation of potassium perchlorate. Chromium (III) oxide was not oxidized by ammonium perchlorate, but oxidation to the hexavalent state took place when potassium chloride was present.
5 citations
TL;DR: In this paper, the thermal decomposition of an intimate mixture of thallium(I) perchlorate and chromium(III) oxide revealed that chromium-III oxide lowers the decomposition temperature of the mixture and is oxidized into hexavalent state.
Abstract: Thermal decomposition of an intimate mixture of thallium(I) perchlorate and chromium(III) oxide revealed that chromium(III) oxide lowers the decomposition temperature of thallium(I) perchlorate and is oxidized into hexavalent state to give thallium(I) dichromate. The thermal decomposition was followed by constant temperature heating, thermogravimetry and differential thermal analysis. The reaction products were characterized by chemical analysis, X-ray diffraction and infrared spectral measurements.
3 citations
TL;DR: In this article, the reaction in the solid state between silver sulfate and calcium oxide was investigated; the reaction proceeded at lower temperatures than previously reported, and the solid products were identified by X-ray diffraction.
Abstract: The reaction in the solid state between silver sulfate and calcium oxide was investigated; the reaction proceeded at lower temperatures than previously reported. The solid products were identified by X-ray diffraction.
2 citations
TL;DR: In this article, the thermal properties of chromium(III) perchlorate have been investigated using X-ray powder diffraction patterns and infrared spectral measurements, followed by TG and DTA techniques.
Abstract: Thermal behaviour of intimate mixtures of chromium(III) oxide and lithium1, potassium2, rubidium3, cesium3 and thallium(I)4 perchlorates revealed that chromium(III) oxide not only catalyses the decomposition by lowering the decomposition temperatures of the pure metal perchlorates but also chemically interacts resulting in the formation of metal dichromate. The oxidation of chromium(III) into the hexavalent state is attributed to the abstraction of oxygen from the perchlorate moiety during the decomposition. In this context, it was thought interesting to study the thermal behaviour of chromium(III) perchlorate and to identify the decomposition products in order to find out whether chromium(III) is oxidized into chromium(VI) by the perchlorate group. Except for a report5 on the preparation of chromium(III) perchlorate with different molecules of water of hydration no work seems to have been carried out on the thermal decomposition of this compound. In the present study, the decomposition characteristics are followed by TG and DTA techniques and the decomposition products have been examined by chemical analysis, X-ray powder diffraction patterns and infrared spectral measurements.
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TL;DR: In this article, the influence of the oxides TiO2, V2O5, Co2O3, MnO2 and Tb4O7 on the thermal decomposition of lithium perchlorate trihydrate was surveyed.
Abstract: The influence of the oxides TiO2, V2O5, Co2O3, MnO2, Fe2O3, Co2O3, NiO, CuO, La2O3, CeO2, Pr6O11, Eu2O3, Gd2O3 and Tb4O7 on the thermal decomposition of lithium perchlorate trihydrate, was surveyed. Most of the oxides lowered the decomposition temperature of the anhydrous perchlorate; but their weight-loss matched the results obtained by heating lithium perchlorate without additives. Chromium(III) oxide and vanadium(V) oxide were exceptional.
8 citations
1 citations