查看“︁酸式焦磷酸钠”︁的源代码

{{chembox
| Name = 焦磷酸二氢二钠
| ImageFile = Disodium pyrophosphate.png
| ImageSize = 200px
| ImageName = 焦磷酸二钠
| IUPACName = Disodium dihydrogen diphosphate
| OtherNames = 酸式焦磷酸钠<br/>焦磷酸二钠<br/>E 450a<br/>E 450(i)<br />SAPP<br>焦磷酸二氢钠
| Section1 = {{Chembox Identifiers
| CASNo = 7758-16-9
| CASNo_Ref = {{cascite|correct|CAS}}
|    EINECS  =  231-835-0
  |  PubChem  =  24451
|  UNII_Ref  = {{fdacite|correct|FDA}}|  UNII  =  H5WVD9LZUD
|  ChemSpiderID_Ref  = {{chemspidercite|changed|chemspider}}|  ChemSpiderID  =  22859
|  SMILES  =  [Na+].[Na+].[O-]P(=O)(O)OP([O-])(=O)O
|  InChI  =  1/2Na.H4O7P2/c;;1-8(2,3)7-9(4,5)6/h;;(H2,1,2,3)(H2,4,5,6)/q2*+1;/p-2
|  InChIKey  =  GYQBBRRVRKFJRG-NUQVWONBAI
|  StdInChI_Ref  = {{stdinchicite|changed|chemspider}}|  StdInChI  =  1S/2Na.H4O7P2/c;;1-8(2,3)7-9(4,5)6/h;;(H2,1,2,3)(H2,4,5,6)/q2*+1;/p-2
|  StdInChIKey_Ref  = {{stdinchicite|changed|chemspider}}|  StdInChIKey  =  GYQBBRRVRKFJRG-UHFFFAOYSA-L

}}
| Section2 = {{Chembox Properties
|   Formula = Na<sub>2</sub>H<sub>2</sub>P<sub>2</sub>O<sub>7</sub>
|   MolarMass = 221.94
|   Appearance = 白色无味粉末
|   Density = 1.1-1.3 g/cm<sup>3</sup>
|   MeltingPt = >600 °C
|   BoilingPt = 
|   Solubility = 11.9 g / 100 ml (20 °C)
  }}
| Section8 = {{Chembox Related
|   OtherAnions = [[磷酸氢二钠]]
|   OtherCations = [[酸式焦磷酸钾]]
|   OtherCpds = [[焦磷酸钠]]
  }}
}}

'''酸式焦磷酸钠'''，化学式Na<sub>2</sub>H<sub>2</sub>P<sub>2</sub>O<sub>7</sub>。

==性质==
酸式焦磷酸钠是一种白色[[单斜]]结晶性粉末或熔融状固体，溶于水，不溶于乙醇。稍有吸湿性，吸水后形成六水合物。水溶液用稀酸加热则水解成[[磷酸]]。加热至220°C以上时分解生成[[偏磷酸钠]]。<ref name="zghg">中国化工产品大全 上卷，Bc288 食用酸式焦磷酸钠，页260</ref>

==制备==
由无水[[磷酸二氢钠]]在140～200°C进行加热熔融聚合，经粉碎后包装，制得食用酸式焦磷酸钠。<ref name="zghg" />
:<math>\rm \ 2NaH_2PO_4\rightarrow Na_2H_2P_2O_7+H_2O</math>

==用途==
酸式焦磷酸钠用作发酵粉，用于烘烤食品，控制发酸速度，提高生产强度。用于方便面和饼干糕点中。<ref name="zghg" />

==参考资料==
{{reflist}}

{{钠化合物}}
{{焦磷酸盐}}

[[Category:钠化合物]]
[[Category:焦磷酸盐]]
[[Category:酸式盐]]
[[Category:缺少物质图片的化学品条目]]