حمض التلوريك

حمض التلوريك
الأسماء
	اسم أيوپاك Hexahydroxidotellurium
	أسماء أخرى Orthotelluric acid, Tellurium(VI) hydroxide
المُعرِّفات
رقم CAS
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:30463 ;
ChemSpider	55517 ;
ECHA InfoCard	100.029.334
PubChem CID	62686;
UNII	WE1KZR49WU ;
CompTox Dashboard (EPA)	DTXSID5064887 ;
	InChI InChI=1S/H2O4Te/c1-5(2,3)4/h(H2,1,2,3,4) Key: XHGGEBRKUWZHEK-UHFFFAOYSA-N ; InChI=1/H2O4Te/c1-5(2,3)4/h(H2,1,2,3,4) Key: XHGGEBRKUWZHEK-UHFFFAOYAT;
	SMILES O[Te](O)(O)(O)(O)O;
الخصائص
الصيغة الجزيئية	Te(OH); 6
كتلة مولية	229.64 g/mol
المظهر	White monoclinic crystals
الكثافة	3.07 g/cm3
نقطة الانصهار
قابلية الذوبان في الماء	50.1 g/100 ml at 30 °C
الحموضة (pKa)	7.68, 11.0 at 18 °C
البنية
الشكل الجزيئي	octahedral
Dipole moment	0 D
المخاطر
خطر رئيسي	corrosive
مركبات ذا علاقة
أنيونات أخرى	Hydrotelluric acid; Tellurous acid; Hydrogen telluride
مركـّبات ذات علاقة	Teflic acid; Sulfuric acid; Selenic acid
	ما لم يُذكر غير ذلك، البيانات المعطاة للمواد في حالاتهم العيارية (عند 25 °س [77 °ف]، 100 kPa).
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	مراجع الجدول

حمض التلوريك Telluric acid هو مركب كيميائي صيغته Te(OH)
6. وهو صلب أبيض معمول من جزيئات Te(OH)
6 ثمانية الأسطح which persist in aqueous solution.^[2] There are two forms, rhombohedral and monoclinic, and both contain octahedral Te(OH)
6 molecules.^[3] Telluric acid is a weak acid which is dibasic, forming tellurate salts with strong bases and hydrogen tellurate salts with weaker bases or upon hydrolysis of tellurates in water.^[3]^[4] It is used as tellurium-source in the synthesis of oxidation catalysts.^[5]^[6]^[7]

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

التحضير

Telluric acid is formed by the oxidation of tellurium or tellurium dioxide with a powerful oxidising agent such as hydrogen peroxide, chromium trioxide or sodium peroxide.^[3]

TeO
2 + H
2O
2 + 2 H
2O → Te(OH)
6

Crystallization of telluric acid solutions below 10 °C gives Te(OH)
6·4H₂O.^[2] It is oxidizing, as shown by the electrode potential for the reaction below, although it is kinetically slow in its oxidations.^[3]

H
6TeO
6 + 2 H+
+ 2 e−
⇌ TeO
2 + 4 H
2O, E^o = +1.02 V

Chlorine, by comparison, is +1.36 V and selenous acid is +0.74 V in oxidizing conditions.

الخصائص والتفاعلات

The anhydrous acid is stable in air at 100 °C but above this it dehydrates to form polymetatelluric acid, a white hygroscopic powder (approximate composition (H
2TeO
4)
10), and allotelluric acid, an acid syrup of unknown structure (approximate composition (H
2TeO
4)
3(H
2O)
4).^[8]^[2]

Typical salts of the acid contains the anions [Te(O)(OH)
5]−
and [Te(O)
2(OH)
4]²⁻. The presence of the tellurate ion TeO2−
4 has been confirmed in the solid state structure of Rb
6[TeO
5][TeO
4].^[9] Strong heating at over 300 °C produces the α crystalline modification of tellurium trioxide, α-TeO
3. ^[4] Reaction with diazomethane gives the hexamethyl ester, Te(OCH
3)
6.^[2]

Telluric acid and its salts mostly contain hexacoordinate tellurium.^[3] This is true even for salts such as magnesium tellurate, MgTeO
4, which is isostructural with magnesium molybdate and contains TeO
6 octahedra.^[3]

أشكال أخرى من حمض التلوريك

Metatelluric acid, H
2TeO
4, the tellurium analogue of sulfuric acid, H
2SO
4, is unknown. Allotelluric acid of approximate composition (H
2TeO
4)
3(H
2O)
4, is not well characterised and may be a mixture of Te(OH)
6 and (H
2TeO
4)
n.^[2]

أحماض التلوريوم الأخرى

Tellurous acid H
2TeO
3, containing tellurium in its +4 oxidation state, is known but not well characterised. Hydrogen telluride is an unstable gas that forms hydrotelluric acid upon addition to water.

المراجع

^ ^أ ^ب Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, Florida: CRC Press, ISBN 0-8493-0594-2
^ ^أ ^ب ^ت ^ث ^ج Greenwood, N. N. (1997). Chemistry of the Elements (2nd Edition ed.). Oxford:Butterworth-Heinemann. ISBN 0-7506-3365-4. {{cite book}}: |edition= has extra text (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
^ ^أ ^ب ^ت ^ث ^ج ^ح قالب:Cotton&Wilkinson6th
^ ^أ ^ب Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
^ "Surface chemistry of phase-pure M1 MoVTeNb oxide during operation in selective oxidation of propane to acrylic acid". J. Catal. 285: 48–60. 2012.
^ "Multifunctionality of Crystalline MoV(TeNb) M1 Oxide Catalysts in Selective Oxidation of Propane and Benzyl Alcohol". ACS Catalysis. 3: 1103–1113. 2013.
^ Yun, Yang Sik; Lee, Minzae; Sung, Jongbaek; Yun, Danim; Kim, Tae Yong; Park, Hongseok; Lee, Kyung Rok; Song, Chyan Kyung; Kim, Younhwa; Lee, Joongwon; Seo, Young-Jong (2018-12-05). "Promoting effect of cerium on MoVTeNb mixed oxide catalyst for oxidative dehydrogenation of ethane to ethylene". Applied Catalysis B: Environmental (in الإنجليزية). 237: 554–562. doi:10.1016/j.apcatb.2018.06.025. ISSN 0926-3373.
^ Loub, J.; Haase, W.; Mergehenn, R. (1979). "Structure of an adduct of orthotelluric acid and urea". Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry. 35 (12): 3039–3041. doi:10.1107/S0567740879011286.
^ Catherine E. Housecroft; Alan G. Sharpe (2008). "Chapter 16: The group 16 elements". Inorganic Chemistry, 3rd Edition. Pearson. p. 526. ISBN 978-0-13-175553-6.

[CRC-1] أ ^ب Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, Florida: CRC Press, ISBN 0-8493-0594-2

[Greenwood-2] أ ^ب ^ت ^ث ^ج Greenwood, N. N. (1997). Chemistry of the Elements (2nd Edition ed.). Oxford:Butterworth-Heinemann. ISBN 0-7506-3365-4. {{cite book}}: |edition= has extra text (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)

[Cotton-3] أ ^ب ^ت ^ث ^ج ^ح قالب:Cotton&Wilkinson6th

[holleman-4] أ ^ب Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.

[5] "Surface chemistry of phase-pure M1 MoVTeNb oxide during operation in selective oxidation of propane to acrylic acid". J. Catal. 285: 48–60. 2012.

[6] "Multifunctionality of Crystalline MoV(TeNb) M1 Oxide Catalysts in Selective Oxidation of Propane and Benzyl Alcohol". ACS Catalysis. 3: 1103–1113. 2013.

[7] Yun, Yang Sik; Lee, Minzae; Sung, Jongbaek; Yun, Danim; Kim, Tae Yong; Park, Hongseok; Lee, Kyung Rok; Song, Chyan Kyung; Kim, Younhwa; Lee, Joongwon; Seo, Young-Jong (2018-12-05). "Promoting effect of cerium on MoVTeNb mixed oxide catalyst for oxidative dehydrogenation of ethane to ethylene". Applied Catalysis B: Environmental (in الإنجليزية). 237: 554–562. doi:10.1016/j.apcatb.2018.06.025. ISSN 0926-3373.

[8] Loub, J.; Haase, W.; Mergehenn, R. (1979). "Structure of an adduct of orthotelluric acid and urea". Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry. 35 (12): 3039–3041. doi:10.1107/S0567740879011286.

[InorgChem-9] Catherine E. Housecroft; Alan G. Sharpe (2008). "Chapter 16: The group 16 elements". Inorganic Chemistry, 3rd Edition. Pearson. p. 526. ISBN 978-0-13-175553-6.

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