게시판 > 질답게시판 > MgCl2 분해 온도를 알고 싶습니다.

스테파노 Stefano

13-11-27 11:51

MgCl2*6H2O의 Boiling Point가 1412℃ (http://avogadro.chem.iastate.edu/msds/mgcl2-6h2o.htm)라고 되어 있는데 이는 MgCl2*6H2O가 분해되어 다음과 같이 변화, 즉
MgCl2*6H2O --------->MgO + 2HCl + 5H2O.

로 반응되는 온도가 160℃ 정도임을 감안하면 아마 Anhydrous MgCl2의 융점이라고 인식되며, 이를 미루어 짐작하면 1412℃보다 높은 온도에서 다음의 Pasma 상태의 온도가 될 것으로 봅니다.

MgCl2---->Mg(2+) + 2Cl(-) -->Mg + Cl2................ ???

<참고>
* MgCl2*x(H2O) Melting Point wrt(with respect to) coordination number of water:
x = 12 (−16.4 °C), 8 (−3.4 °C), 6 (116.7 °C), 4 (181 °C), 2 (ca. 300 °C).
* Boiling Point of MgCl2*6H2O : 1412℃ (http://avogadro.chem.iastate.edu/msds/mgcl2-6h2o.htm)

sksskzdlek hosgive

13-12-03 17:26

감사합니다.

근데 위 반응

MgCl2*6H2O → MgO + 2HCl + 5H2O

이 160℃ 에서 일어난다는 말씀이신가요?

스테파노 Stefano

13-12-09 19:49

다음 내용으로부터 판단 하세요

http://www.scientific.net/MSF.724.425

http://www.sciencedirect.com/science/article/pii/S0165237011000349

The thermal decomposition mechanisms and the intermediate morphology of MgCl2·6H2O and MgCl2·H2O were studied using integrated thermal analysis, X-ray diffraction, scanning electron microscope and chemical analysis. T

he results showed that there were six steps in the thermal decomposition of MgCl2·6H2O: producing MgCl2·4H2O at 69 °C, MgCl2·2H2O at 129 °C, MgCl2·nH2O (1 ≤ n ≤ 2) and MgOHCl at 167 °C, the conversion of MgCl2·nH2O (1 ≤ n ≤ 2) to Mg(OH)Cl·0.3H2O by simultaneous dehydration and hydrolysis at 203 °C, the dehydration of Mg(OH)Cl·0.3H2O to MgOHCl at 235 °C, and finally the direct conversion of MgOHCl to the cylindrical particles of MgO at 415 °C.

To restrain the sample hydrolysis and to obtain MgCl2·H2O, MgCl2·6H2O was first calcined in HCl atmosphere until 203 °C when MgCl2·H2O was obtained; HCl gas was then turned off and the calcination process continued, producing Mg3Cl2(OH)4·2H2O calcined at 203 °C, Mg3(OH)4Cl2 at 220 °C and MgO at 360 °C.

The temperature of producing MgO from calcination of MgCl2·H2O was lower (360 °C) than that from MgCl2·6H2O (415 °C) because of its more reactive intermediate products: the irregular shape and tiny needle-like Mg3Cl2(OH)4·2H2O particles and the uneven surface porous Mg3(OH)4Cl2 particles. The MgO particles obtained at 360 °C had a flake structure.

다음 내용으로부터 판단 하세요

http://www.scientific.net/MSF.724.425

http://www.sciencedirect.com/science/article/pii/S0165237011000349

The thermal decomposition mechanisms and the intermediate morphology of MgCl2·6H2O and MgCl2·H2O were studied using integrated thermal analysis, X-ray diffraction, scanning electron microscope and chemical analysis. T

he results showed that there were six steps in the thermal decomposition of MgCl2·6H2O: producing MgCl2·4H2O at 69 °C, MgCl2·2H2O at 129 °C, MgCl2·nH2O (1 ≤ n ≤ 2) and MgOHCl at 167 °C, the conversion of MgCl2·nH2O (1 ≤ n ≤ 2) to Mg(OH)Cl·0.3H2O by simultaneous dehydration and hydrolysis at 203 °C, the dehydration of Mg(OH)Cl·0.3H2O to MgOHCl at 235 °C, and finally the direct conversion of MgOHCl to the cylindrical particles of MgO at 415 °C.

To restrain the sample hydrolysis and to obtain MgCl2·H2O, MgCl2·6H2O was first calcined in HCl atmosphere until 203 °C when MgCl2·H2O was obtained; HCl gas was then turned off and the calcination process continued, producing Mg3Cl2(OH)4·2H2O calcined at 203 °C, Mg3(OH)4Cl2 at 220 °C and MgO at 360 °C.

The temperature of producing MgO from calcination of MgCl2·H2O was lower (360 °C) than that from MgCl2·6H2O (415 °C) because of its more reactive intermediate products: the irregular shape and tiny needle-like Mg3Cl2(OH)4·2H2O particles and the uneven surface porous Mg3(OH)4Cl2 particles. The MgO particles obtained at 360 °C had a flake structure.