查看“︁二氧化钍”︁的源代码

{{chembox
| Reference = <ref name="webelements">[http://www.webelements.com/compounds/thorium/thorium_dioxide.html Thoriumdioxid bei webelements.com].</ref>
| Name = 二氧化钍
| ImageFile = Fluorite-unit-cell-3D-ionic.png
| ImageFile1 = CaF2 polyhedra.png
| IUPACName = Thorium dioxide<br>Thorium(IV) oxide
| OtherNames = 氧化钍
|Section1={{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 1314-20-1
| PubChem = 14808
| InChI = 1S/2O.Th
| SMILES = O=[Th]=O
  }}
|Section2 = {{Chembox Properties
|   Formula = ThO<sub>2</sub>
|   MolarMass = 264.04
|   Appearance = 重质白色无臭结晶粉末
|   Density = 10.00 g/cm<sup>3</sup>
|   Solubility = 不溶于水
|   SolOther = 不溶于[[碱]]<br />微溶于[[酸]]
|   MeltingPt = 3390 °C
|   BoilingPt = 4400°C
|   RefractIndex = 2.200 (方钍石)
  }}
| Section3 = {{Chembox Structure
|   CrystalStruct = [[萤石]] (立方晶系), ''cF12''
|   SpaceGroup = Fm<u style="text-decoration:overline">3</u>m, No. 225 
|   Coordination = 四面体 (O<sup>2–</sup>); 立方 (Th<sup>IV</sup>)
<!--
|   LattConst_a = 559.74(6) pm<ref>{{citation | title = Thermal expansions of NpO<sub>2</sub> and some other actinide dioxides | journal = J. Nucl. Mat. | volume = 245 | issue = 1 | year = 1997 | pages = 72–78 | author= Yamashita, Toshiyuki; Nitani, Noriko; Tsuji, Toshihide; Inagaki, Hironitsu| doi = 10.1016/S0022-3115(96)00750-7}}</ref>
-->
  }}
| Section4 = {{Chembox Thermochemistry
|   DeltaHf = −1226(4) kJ/mol
|   Entropy = 65.2(2) J K<sup>−1</sup> mol<sup>−1</sup>
  }}
| Section7 = {{Chembox Hazards
|   ExternalMSDS = 
|   MainHazard = 放射性
|   EUClass = 有毒 ('''T''')
|   RPhrases = {{R23/24/25}}, {{R33}}, {{R45}}
|   SPhrases = {{S36/37/39}}, {{S45}}, {{S53}}
|   LD50 = 400 mg·kg<sup>−1</sup> (小鼠经口)<ref name="BOC">[http://www.bocedwards.com/pdf/P120-10-000_Ionisations-Messr%C3%B6hren.PDF BOC Edwards Sicherheitsdatenblatt].</ref>
  }}
| Section8 = {{Chembox Related
|   OtherAnions = 
|   OtherCations = [[二氧化铪]]<br />[[二氧化铈]]
|   OtherFunctn = 
|    Function = 
|   OtherCpds = [[二氧化镤]]<br/>[[二氧化铀]]
  }}
}}

'''二氧化钍'''，别名'''氧化钍'''，化学式ThO<sub>2</sub>。
==制备==
[[硝酸钍]]溶液与[[草酸]]溶液反应沉淀出[[草酸钍]]。经过滤、洗涤、干燥，并在650～800°C下灼烧，制得二氧化钍。
:<math>\ Th(NO_3)_4+2H_2C_2O_4\rightarrow Th(C_2O_4)_2+4HNO_3</math>
:<math>\ Th(C_2O_4)_2\rightarrow ThO_2+2CO_2+2CO</math>
==物理性质==
二氧化钍是不溶于水的重质白色粉末，有[[放射性]]。[[莫氏硬度]]为6.5。
==化学性质==
二氧化钍可以被金属[[钙]]在1000℃还原：
: ThO<sub>2</sub> + 2 Ca → 2 CaO + Th
==用途==
用作耐火材料、催化剂，也用于制造原子能燃料、光学玻璃、电子管阴极、高温陶瓷和白炽灯等。以前亦用作[[顯影劑]]，唯因安全問題已棄用<ref>[https://radiopaedia.org/articles/thorotrast Thorotrast] {{Wayback|url=https://radiopaedia.org/articles/thorotrast |date=20211026054416 }}. radiopaedia.org</ref>。

==参考资料==
{{reflist}}

{{钍化合物}}
{{氧化物}}

[[Category:钍化合物]]
[[Category:氧化物]]
[[Category:缺少物质图片的化学品条目]]

{{无机化合物小作品}}