Thermal Decomposition of Ammonium Salts of Transition Metal Oxyacids. V. Study on the Thermal Decomposition of Ammonium Metavanadate

전위금속의 산소산염의 열분해에 관한 연구 (제5보) Ammonium Metavanadate의 열분해에 따르는 $V_2O_5$의 생성

  • Il-Hyun Park (Department of Chemistry, Sung Kyun Kwan University)
  • 박일현 (成均館大學校 理工大學 化學科)
  • Published : 1972.06.30

Abstract

Thermal decomposition of ammonium metavanadate has been investigated by using the quartz spring balance and differential thermal analysis. It showed that the decomposition of ammonium metavanadate is proceeded at two stages which correspond to $180^{\circ}C-220^{\circ}C$ and $310^{\circ}C-330^{\circ}C$ decomposition temperatures, respectively. Evolved ammonia gas in thermal decomposition has been analyzed quantitatively by titration. And the constituents of gases evolved have been evaluated by gas chromatography and omegatron spectrometer. From these results, it was concluded that the gases evolved in the first step decomposition were $NH_3$ and $H_2O$ with 2:1 ratio and the second step decomposition corresponded to the formation of $NH_3$, $H_2O$ and $N_2O$ which was produced in oxidation of $NH_3$ by $V_2O_5$. The decomposition products were identified by means of X-ray diffraction method. The decomposition product in air was V_2O_5 and the product in vacuum $V_3O_7.$ The kinetics of the thermal decomposition was studied, giving the values of the activation energy of 41.4 kcal/mole and 64.4 (kcal/mole) respectively.

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References

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